THE

JOURNAL OF

COMPARATIVE PATHOLOGY AND

THERAPEUTICS.

VOL. XXV L-N o. 2. JUNE 30, 1913. PRICE 2S. 6d.

ANAPLASMS OR JOLLY BODIES?

A CONTRIBUTION TO THE KNOWLEDGE OF CERTAIN INTRA­CORPUSCULAR BODIES PRESENT IN THE BLOOD OF SOME SPECIES OF MAMMALS.

By SYDNEY DODD, D.V.Sc., F.R.C.V.S., Veterinary Pathological Laboratory, The University of Sydney, New South Wales.

SINCE Theiler 1 published the results of his investigations upon the nature of certain bodies occurring in the erythrocytes of cattle in South Africa, and to which he gave the name of anaplasm, a great deal of interest and some discussion has been aroused as to the significance of morphologically and tinctorially similar bodies some­times observed in the red blood corpuscles of other species of animals in other parts of the world. Such bodies have been described as occurring in man in cases ofleukcemia, and in the horse, donkey, sheep, goat, pig, cat, marsupials, monotremes, and the Australian dingo (native dog).6 Their presence in the blood of various species of wild animals, viz., lemurs, the mouse deer, the orang-utang, the Capuchin monkey, etc., is set forth in the following article, with some observa­tions as to their probable origin and significance.

The interest in what Balfour calls "these enigmatical bodies" is increased owing to the fact that Theiler showed in his experiments that the anaplasms of cattle in South Africa have a pathological significance, being, he concludes, responsible for certain abnormal conditions in their host, and that they could be transmitted from affected to healthy cattle by artificial inoculation and naturally by ticks.

What are presumedly the same bodies have been noted in the blood of cattle in North and South America.

It has already been mentioned that bodies morphologically similar G

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to those described by Theiler have been found in species of animals other than cattle, and the observers have arrived at various con­clusions as to their nature. In some instances it was either concluded at once that the bodies so found were identical with Theiler's anaplasms, or their parasitic nature was declared upon what appears to be insufficient evidence.

The presence of small, rounded chromatin bodies in the red blood corpuscles was, according to Balfour, first described by Jolly in the blood of rodents, and they are therefore usually called" Jolly bodies."

The view held by their discoverer as to their origin was that they probably resulted from hydration of the stroma of the corpuscle. Another view, held by Cabot and others, is that they are chromatin remnants of the red cell. (I am not aware that anyone has advanced the opinion that the chromatin bodies in the erythrocytes of rodents are parasitic.)

Up to the present, however, no convincing evidence has been brought forward to show whether the chromatin bodies discovered in the blood of animals other than cattle or rodents should be classified with the anaplasmata of Theiler or with the bodies of Jolly. Bruce 2

has expressed the opinion that the parasitic nature of the chromatin bodies observed by him in the blood of calves and goats in Uganda was not proved. Jowett 3 rec6lrds the presence of anaplasms in the blood of cats, although Morris 4 states that portions of the nuclear matter of the red cells occur normally in the circulating blood of these animals. Balfour 5 considers that certain bodies found by him in the erythrocytes of donkeys in the Sudan were anaplasms and not Jolly bodies, although the grounds for arriving at such a conclusion do not appear altogether convincing. I n an article by Sweet, Gilruth, and Dodd 6 on the presence of bodies apparently identical with anaplasma margin ale in the blood of various animals, chiefly marsupials and monotremes, the opinion was expressed that they were possibly parasitic but with no pathological significance. The last-named author is, however, of the opinion that the evidence is decidedly ag~inst their parasitic nature, as will be shown later on.

As it is desirable that all existing knowledge concerning these b odies should be collected, in order to arrive at some definite con­clusion as to their exact nature, the following observations have been recorded. They have been made upon nearly 300 animals (excluding­those of the domestic species), comprising a variety of orders. The g reat majority of them were obtained from the gardens of the Royal Zoological Society, Sydney. Nearly all of the examinations were made post-mortem, but in a number of positive cases blood was also

-obtained from the living animal.

Chromatin Bodies in tite Erythrocytes of the Tragulidce. The member of the above order in which the bodies were found

was the so-called mouse deer of Java (tragulus javanicus). These little animals are very interesting in several respects. Theyare about the size of a whippet dog and superficially resemble deer. Anatomically, however, they are more related to the pig family than the deer. Another point of interest is the minute size of their red corpuscles, of which the average diameter is about 2'5 ft. The above species of tragulidce is very common in Java.

Early in 191 I three mouse deer arrived at the Zoological Gardens,

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Sydney, from Java:. They had been captured only a few weeks previously, and apparently were in good health on arrival. One died on 25th October, about two weeks after admission. The apparent illness was of short duration, and no gross lesions were seen on post-mortem examination, except that the tissues generally were <:edematous. Trypanosomes (trypanosoma ingens) and micro-filarice were present in the general blood stream, also an occasio~al piro­plasm of the mutans type. In addition to these organisms, there were present fairly abundantly in the erythrocytes very minute ·spherical dots taking the chromatin stain. Reference to the figures (see fig. 4) will enable one to appreciate the size of these bodies in .comparison with those from other animals. There was nothing in their tinctorial characters or morphology except size to distinguish them from the chromatin bodies found in the marsupials, lemurs,

FIG. 1.

·etc., the Jolly bodies in rodents, or from the anaplasms. Some showed a distinctly marginal disposition, while others occupied 'various other positions in the red blood cells. There was very little variation in the size of the dots. Those observed were all single, no ' double ones being demonstrated. The bodies were relatively fairly numerous, one or more occurring in every field of the ·microscope.

The other two mouse deer died on 29th October 1911 and 21st April 1912, respectively. Micro-filarice and trypanosomes were present in their blood, but the chromatin bodies observed in the -red blood cells of the first animal were totally absent.

Chroma#n Bodies in Lemurs. Case No. I.-On 1st May 1912 a ring-tailed lemur (lemur catta)

·died unexpectedly at the Zoological Gardens, Sydney. No previous illness had been observed by the keepers. The result of the autopsy was as follows.

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The abdominal cavity contained a large quantity of blood. The liver was enlarged and in a state of very advanced fatty degeneration. A ragged rupture extended from the lower border of the left lobe for about an inch into the substance of the organ. The spleen was· slightly swollen and the capsule exhibited a peculiar mottling. It was also softer than normal. The heart was dilated and flabby_ The lungs were blanched and the kidneys swollen.

Microscopical examination of the blood showed the presence of numerous normoblasts and polychromatophilia; also in the red cells numerous spherical bodies taking the chromatin stain and of a fairly uniform size, somewhat about that of ordinary staphylococci. A few,. however, were merely dots, although distinctly taking the chromatin stain. Another noticeable feature was that the bodies were distinctly marginal in their disposition.

Case No. 2.-Mongoose lemur (lemur mongoz). Died at the' Zoological Gardens 9th May 1912. Had been visibly ill for some' days.

Autopsy.-The liver contained a number of necrotic foci scattered throughout the parenchyma, each about the size of a lentil. The spleen also showed a number of similar areas of about the same size. On section the nodules had a dry, dirty-white appearance. The kidneys were softened and clay coloured. The other organs were normal in appearance. The red blood corpuscles contained a number of chromatin bodies resembling in every respect those present in case No. I. There were no other marked lesions. The nodules. contained bacteria of the colon type. Whether these were the primary cause of the necrotic foci or whether they were secondary invaders need not be discussed here.

Case No. 3.-Ring-tailed lemur. Died suddenly 13th May 1912. Autopsy.-The liver showed advanced fatty degeneration, with a,

few petechia': scattered over the surface of the organ. The kidneys. were congested and the heart distended. The red corpuscles con­tained chromatin bodies as in the two previous cases, but they were not so numerously present. Blood lesions were otherwise absent.

Case No. 4.-Ring-tailed lemur. A young animal, born in the Zoological Gardens. Died suddenly on 14th August 1912, no, previous signs of illness having been observed.

Autopsy.-Liver congested and friable. Kidneys blanched. No other gross lesions. The blood showed numerous normoblasts,. moderate polychromatophilia, and marked anisocytosis. Only one chromatin body could be detected in a smear.

Case No. 5.-Ring-tailed lemur. This animal had been ailing for some days, and died 8th June I9I2.

Post-mortem examination was not held until forty hours after, but owing to the cold weather decomposition was not too far advanced. No gross lesions could be detected except that the ca':cum was markedly congested. Scrapings from the mucous membrane revealed numerous balantidium coli in addition to the usual bacterial flora. Chromatin bodies were very scanty in the blood, only two being found in a smear. The erythrocytes themselves were normal.

Naturally the presence of these intracorpuscular bodies in greater' or smaller numbers in all of the five dead lemurs examined aroused a considerable amount of interest. In cases Nos. 1 and 2 the pro-

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1I10unced fatty degeneration of the liver in both, and the rupture of that organ in one animal, must have been secondary causes of death and not primary. The presence of identical bodies in the red blood cells of two lemurs that had apparently died from bacterial infection did not lessen the interest, as the bacterial invasion of the liver might well have heen a secondary condition, as might also in the case of NO.4, the typhlitis, which was probably due to balantidium coli. In view of the foregoing, it became necessary to ascertain whether the chromatin bodies present in the dead lemurs were also present in the apparently healthy living ones. Blood smears were therefore obtained from four different species of lemur then present in the Zoological Gardens. Two animals of each species were examined, making a total of eight, viz.: ring - tailed lemur (lemur catta), mongoose lemur (lemur mongoz), black lemur (lemur macaco), crown lemur (lemur coronatus).

F IG. 2.

All of these appeared to be quite healthy at the time of taking their blood, with the exception of a ring-tailed lemur, No. 1. This animal died about two weeks after the smears were taken.

Post-mortem.-Decomposition was' too far advanced when the body was received for any useful information to be gained as to the lesions present. Chromatin bodies were, however, scantily present in the red blood corpuscles.

The results of the microscopical examination of the blood films from the above eight animals were as follows.,

No. I.-Ring-tailed lemur. An aged animal. Had been in the Gardens for a considerable but undetermined period. Chromatin bodies very scantily present in the red cells. No special disposition in . the corpuscles. Size of the bodies varied. Slight polychromato­philia. This animal was ill at the time of taking the blood and died subsequently (vide above).

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No.2. - Ring - tailed lemur. Quite healthy in appearance. Chromatin bodies numerous. A few normoblasts present. The bodies were of varying size and disposition, but mainly on or near the margins of the corpuscles. A few dividing forms present. Moderate anisocytosis and polychromatophilia.

No. 3.-Mongoose lemur. An old animal, had been in the Gardens for several years. Chromatin bodies fairly numerous, principally marginal. A few dividing forms. Size varying.

NO.4.-Mongoose lemur. A young animal, not full grown. Was born in the Gardens. Chromatin bodies fairly numerous. Size varying. No special disposition in the corpuscles.

No. 5.-Crown lemur. An adult animal. Chromatin bodies present but very scanty. No special disposition. One normoblast seen.

No. 6.-Crown lemur. An adult animal. Chromatin bodies present but scarce. Slight polychromatophilia.

No. 7.-Black adult lemur. Chromatin bodies fairly numerous, one or two in every field of the microscope. Size and disposition varied.

No. S.-Black lemur. Half-grown animal. Chromatin bodies very scarce. Only one or two found after prolonged search. Red corpuscles normal.

Chromatin Bodies in the Quadrumana. During the past two years I have examined the blood of twenty­

five members of this order, comprising various species. The examination was in every case carried out post-mortem. Death was due to various causes, most of them ascertained. In

only two of the twenty-five animals were the chromatin bodies under discussion discovered, viz.: (I) A white-fronted Capuchin monkey (cebus albifrons), and (2) an orang-utang (simia satyrus). The following are the details.

(I) White-fronted Capuchin monkey. Received at the Zoologica~ Gardens 3rd September 1912. Died 30th of same month.

Post-mortem E:camination.-An abscess cavity about the size of a. walnut present in the submaxillary space. This had been treated but the pus had burrowed into the parotid region. Metastatic abscesses were present in the lungs, spleen, liver, and kidneys. Blood lesions were marked upon microscopic examination, megalo­cytes being very numerous. Chromatin bodies were plentiful, the size varying considerably, up to that of half the nucleus of a normoblast. They were indifferently disposed within the corpuscle, a number being distinctly marginal. No free bodies were seen in the slides examined, all being intracorpuscular. This fact should be borne in mind, since it may probably be suggested that the bodies found in the blood of this animal were really staphylococci, as these were the cause of the metastatic abscesses, and therefore some of the cocci must have been present in the blood stream. This argument is quite a reasonable one, but the bodies described varied in size too greatly, some being too large and others too small for staphylococci. Besides, all the bodies I observed were inside the red corpuscles; none were free in the plasma. It must, however, be admitted that chromatin bodies and staphylococci cannot be distinguished from

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each other by their staining reactions when the usual chromatin stains are employed, nor by their morphology when both are about the same size.

(2) Orang-utang. The case of this animal is of considerable im­portance, as it appears to afford some direct evidence as to the origin of the intracorpuscular chromatin bodies present in this and other animals. The orang had been in the Zoological Gardens about thirteen months, and died on 24th November 1912. It had been ailing some days before death, and post-mortem examination showed the blood to be heavily infected with ha!moproteus pithed. This malarial protozoon was probably the primary cause of death. In additiQn , there were present in the red corpuscles, both from the general circulation and the organs, a few chromatin bodies morphologically and tinctorially identical with those already

FIG. 3.

described. In the case of this animal, however, smears were made from the bone marrow of the femur, humerus, and ribs. In the case of all the previous animals I had not troubled to make preparations from 'the marrow, having examined the red cells present in the general circulation and organs only. The marrow of the shafts of the long bones was markedly congested, and smears showed chromatin bodies to be relatively numerous. In addition, as of course was to be expected, erythroblasts were plentiful. In a number of the latter the nuclei were undergoing fragmentation, and in a single smear there could be observed all gradations in size, from the intact nucleus down to small spherical fragments quite indis­tinguishable from the chromatin bodies present in the general circulation of this and other animals. Moreover, in some of the red cells small fragments of the size and shape of the bodies in the general blood stream could be seen just about to become detached from the parent nucleus. In others the nucleus having split up into

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rounded lobes was again further subdividing into smaller fragments. Some of these smaller bodies occupied positions right on the margin of the red corpuscle. Cells containing nothing but small rounded fragments like those in the general circulation were common. Occasionally small dividing forms about the size of a coccus or less could be seen. They resembled those observed in the red corpuscles of some of the lemurs (see fig. 6).

Chromatin Bodies in tlte Bone Marrow 0./ the Hog Deer (Cervus Porcinus).

This case is included to show that in some animals at least, although the blood in the vessels and organs is free from chromatin bodies and apparently normal in other respects, yet it may be possible to demonstrate the presence of such bodies in the bone marrow.

The animal in question died on 13th December 1912. It had been an inmate of the Zoological Gardens for a number of years, and up to the time of death no marked illness had been observed.

Post - mortem Examination. - Pregnancy far advanced. Both kidneys markedly affected with sub-acute interstitial nephritis. Other organs apparently normal. Blood normal. No chromatin bodies seen either in general circulation or organs. Marrow from ribs showed a number of chromatin bodies in the erythrocytes. The size of the bodies varied more considerably than those seen in the general circulation of other animals, there being a greater proportion of larger size, up to that of half a nucleus.

GENERAL CONSIDERATIONS CONCERNING THE NATURE OF THE CHROMATIN BODIES IN THE VARIOUS ANIMALS SPECIFIED.

The Marsupials. The occurrence of chromatin bodies in the blood of these animals

has already been recorded,6 and it is only proposed here to discuss their origin, etc.

There IS no evidence at present to substantiate the view that such bodies are of parasitic origin beyond the undoubted fact that they resemble the anaplasms both in morphology and staining reactions. On the contrary, the available evidence all goes to show that the bodies in question are not parasitic, but are purely nuclear remnants, and, furthermore, that they occur normally in the circulating blood of marsupials in general. Nearly every marsupial that I have ex­amined, whether dead or alive, some of the latter in the best of health, presented these bodies in greater or smaller numbers in their erythrocytes. Sometimes they were exceedingly scarce, and necessi­tated prolonged search to demonstrate them. In other animals they were relatively numerous. They appear to have no influence upon the well-being of their host, and up to the present I have not definitely associated their presence in relatively large numbers with any pathological condition, except perhaps the an<emia due to stomach worms. It is, however, legitimate to consider that, though normally almost invariably present, their numbers in the circulating blood may be increased under certain conditions, such as that just mentioned. Inoculation of blood containing the bodies into animals of like

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species, such as was performed by Theiler in the case of anaplasms, in order to demonstrate whether they are transmissible or not, is -quite out of the question, owing to the practical impossibility of -obtaining marsupials with their blood free from such bodies. The bodies have also been shown to be present in marsupials that have been born in captivity, and even in very immature pouch young also born in captivity.

There is considerable variation in the size of the bodies present in marsupials, as, indeed, there is in most other species examined. Their diameter varies from 1'5 fL to 4fL, and is thus much greater than in those seen in other animals. It is of course recognised that this by itself is no proof of their non-parasitic nature.

FIG. 4.

The Lemurs.

It was partly on account of the presence of chromatin bodies in the .erythrocytes of five lemurs, dead within a few weeks of each other, ;that it appeared at first that in these animals at least the bodies might be protozoa, and perhaps primarily responsible for a fatal

1llness. All these species of lemur are natives of Madagascar, and the thought arose that the bodies present in these animals might lreally be anaplasms. Examination, however, of the blood of the living and, except in one case, apparently healthy lemurs caused this tentative opinion to be abandoned, for in all cases of the latter ·chromatin bodies were present in the red corpuscles in greater or smaller numbers. In some instances they were so scarce as to need ;prolonged search of the slide. These bodies were also found to be present in animals that had been born in the Zoological Gardens, .and kept in cages all their lives.

The question then arises whether if the chromatin bodies in the 'red corpuscles of lemurs are not parasitic they are to be considered

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normal to the blood of these animals, just as are probably those of the marsupials, seeing that they were present in the blood of every lemur examined, twelve in all.

The lemurs are much more advanced in the zoological scale than the marsupials, and until more animals have been examined I do not feel justified in drawing the same conclusions as I have in the case of the latter. At present my view is that the presence of these' bodies in the lemurs must be looked upon as an abnormal condition,. but that nevertheless the bodies are identical with those present in the other species of animal discussed in this paper, have the same origin, and therefore should not be classified with the anaplasms. Why they should be so constantly present in the blood of lemurs is· not so easy to explain. It may be that the living lemurs were only apparently healthy, and that conditions which resulted in the appear­ance of chromatin bodies in the dead animals, although not actually the cause of death in the latter, were existing in the living lemurs also. On the other hand, if these bodies are normal to the blood of cats, as is held by Morris, there is reason for admitting that the' similar bodies in lemurs may also ultimately be shown to be normal: to the blood of the latter.

TIle Tragulida:. Of three mouse deer examined, one only showed chromatin bodies·

in the red corpuscles.. In the two that were negative the blood was· examined during life as well as post-mortem.

In connection with this species of animal a point of interest, and perhaps of some value, becomes evident. It has already been stated that the red corpuscles of the mouse deer are only about 2'5fL in diameter, that is, only about a third of the size of those of the other' species of animal examined. As if to correspond with this, the chromatin bodies found therein were also very small as compared with the average body found in the erythrocytes of the other animals. This can be readily appreciated on comparing fig. 4 with figs. I, 2,. and 3. All were drawn to exactly the same scale with the camera lucida. If these bodies were parasitic it would be curious to find the smaller parasite choosing for its habitat the animal with the' smaller erythrocyte. May not the true explanation be that as the nuclei of the erythroblasts in the mouse deer are of a relatively smaller size than those of the other animals, in correspondence with the size of the cell itself, so the fragments resulting from the dis­integration of the nucleus are also relatively smaller than those' present in the larger red cells of other animals?

The Quadrumana. There appears no reason for doubting that the chromatin bodies

present in the blood both of the Capuchin monkey and the orang­utang were nuclear remnants. I have already given my opinion. why they could not be staphylococci in the case of the former, and' the evidence in favour of the nuclear remnants appears to be pretty conclusive in the case of the latter, where, by examination of the' bone marrow, all the steps from the fragmentation of the nucleus to· the presence of only one small body in the erythrocyte could be' demonstrated.

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The other two orangs died soon after arrival in Sydney after a short, acute illness, due apparently to errors in diet. Their blood was, carefully examined, but no chromatin bodies could be found. The third orang in which the bodies were found was iII at the same time,. but recovered after a radical change in diet. It died six months later.,

Post-mortem examination showed that the intestinal trouble had entirely disappeared.

It will be observed that the erythrocytes of the Capuchin monkey" shown in fig. 5, appear larger than normal. This, as is well known, is a common feature in acute cases of septicc.emia and pyc.emia. The interesting feature in this case is that very few normal-sized erythrocytes contained chromatin bodies. The majority were found in the cells above the normal size.

FIG. 5.

CONCLU SIONS.

Although it appears to have been demonstrated that the sphericaD bodies present in the red corpuscles of cattle in South Africa are parasitic and communiCable to animals of the same species, and also· that similar bodies have been observed in the blood of cattle in North and South America, it is a debatable point whether the intracorpuscular bodies giving the reactions of chromatin found in certain other mammals can be considered to belong to the anaplasms,. or whether they are merely products of the cell itself. At present the proofs furnished by the various writers for considering that they should be classified as anaplasms are not very conclusive. The mere presence of small spherical chromatin bodies in the erythrocytes of an animal, although morphologically similar to the anaplasms of Theiler, by no means of itself justifies the definite conclusion that they are parasites and belong to that class of organism. Those instances in which they have been so frequently seen in the blood

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of certain species should perhaps warrant one in withholding such a conclusion. Furthermore, the position of the chromatin body in the cell is also no proof that it is necessarily an ana plasm, for it has been shown that in some insta.nces the bodies in the red cells of some of the animals discussed here were quite marginal in disposition. Also the fact that dividing bodies may be encountered in the erythrocytes is insufficient to justify one in placing such bodies with the anaplasm'5, for it has been made quite evident during the examination of preparations from bone marrow that portions of chromatin material within the red cell may further break up into smaller pieces in such .a way as to look somewhat like living organisms in the process of multiplication by fission.

On the other hand, what is the evidence, in the case of those .animals discussed in this article, that the chromatin bodies present ,in the erythrocytes are not protozoa? There are several points, mostly of a negative character, which cause one to arrive at such a .conclusion, but those bearing most strongly against the parasitic theory are that they may be demonstrated in very young and, in the case of .the marsupials, very immature animals, born in captivity, and in which the probability of natural infection is exceedingly remote; also that by the examination of preparations from the bone marrow .of animals showing such bodies in the erythrocytes of the circulating blood one can observe their process of formation, from the breaking up of the nuclei of the erythroblasts, or the splitting off of fragments from them, down to the small spherical bodies such as are observed in the general circulation, and whose disposition may be marginal or -otherwise. The fact that these bodies have been found in the bone marrow when they were absent from the general circulation is -interesting in conjunction with the other evidence, but, of course, by itself it is no proof of their non-parasitic nature, for one may at times find undoubted protozoa present in the bone marrow in certain .diseases when they cannot be demonstrated elsewhere. I have already indicated that in the mouse deer the size of the chromatin bodies is much less than those of other animals, in corn;spondence with the small size of their erythrocytes. This appears to be another point in favour of the fragmentation of the nucleus view.

In order to check my observations to a certain extent I have examined the blood of numerous young rodents, and find that the chromatin (Jolly) bodies present in their erythrocytes are indi­·stinguishable from those herein described.

The evidence at present appears to be greatly in favour of the view that the chromatin bodies observed in the erythrocytes of marsupials, lemurs, mouse deer, Capuchin monkey, and orang-outang at least are not protozoa, and therefore cannot be classified with the anaplasms, but that they are more probably identical with the bodies -of Jolly. Jolly's view as to the origin of these bodies, viz., that they are due to the hydration of the stroma of the corpuscle, does not appear to be the correct explanation. They rather appear to be purely nuclear remnants, as is held by Cabot and others. One has to admit, however, that at present there is no certain method of .distinguishing microscopically between the anaplasms and the Jolly bodies when they appear in the circulating blood.

The question, then, requiring an answer is, if these bodies are

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non-parasitic but are merely remnants of the nucleus of the red blood cell, what is the cause of their appearance in the blood of animals in which they are not normal?

The case of the marsupials must be taken separately, as it will b<: seen that I consider their presence here a normal occurrence. They represent a very early type of mammal, and it may be that in them we have furnished a link in the gap between the vertebrates with nucleated and those with non - nucleated erythrocytes. In the marsupials the evidence appears to indicate that remnants of some of the nuclei of the red cells, instead of disappearing from the genera1 circulation in late fretal or early extra-uterine life, as in most of the higher mammals, tend to persist in the form of small spherical fragments, so that throughout the life of the animal a greater or smaller number of erythrocytes containing such fragments may be

FIG. 6.

demonstrated in the general circulation. Their presence, therefore, may be viewed as a normal condition. This is not to deny the fact that under certain conditions they may be present in abnormal numbers.

With the other animals specified in this article the condition appears to assume a pathological aspect. It is a well· known fact that the red blood cells of the mammalian embryo are nucleated, but that the nucleus disappears from the erythrocyte in the general circulation during late fretal or early extra-uterine life. Erythro­blasts, however, persist in the bone marrow of the adult. If any condition exists that causes an abnormal destruction of red cells there is usually an increase in the activity of the erythroblasts in order to make up the deficiency. As a result of this, some immature nucleated red cells (normoblasts, etc.) are thrown into the general circulation from the bone marrow. Seeing that this is the case, one might explain the presence of only fragments of the nucleus in the

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,erythrocytes of the circulating blood by considering that some pathological condition exists in which there is a constant abnormal, but not very great drain upon the red cells. The resulting stimula­tion is not great enough for a demonstrable number of red cells with entire nuclei to be thrown into the general circulation, yet it is sufficient to cause a greater or smaller number of cells that have not entirely lost the last remnant of their nucleus to make their appear­ance in the blood stream. Intermediate stages may sometimes be found in which both red cells with entire nuclei and cells with only minute fragments occur together.

As already mentioned, provisionally I prefer to view the presence ·of chromatin bodies in the lemurs as an abnormal condition. Yet the fact that they have been seen in every animal examined might, -on the contrary, indicate that they are normal to the blood of these animals, just as they are considered to be in the cat. This point -can only be decided by examining a large number of lemurs.

Further investigations are still being conducted upon the subject -of the chromatin bodies.

DESCRIPTION OF ILLUSTRATIONS. Drawings, all to same scale, of blood smears, etc., showing chromatin bodies

-in the red corpuscles. Drawn with Abbe's camera lucida. Composite fields. Microscope tube, length 146 mm. Compensating ocular No.8. Apochro­.matic objective, 1'5 mm.. Giemsa stain.

FIG. 1. Blood, vulpine opossum. FIG. 2. Blood, mongoose lemur. FIG. 3. Blood, ring-tailed lemur. iFIG. 4. Blood, mouse deer. FIG. 5. Blood, Capuchin monkey. FIG. 6. Smear from bone marrow, orang-utang.

BIBLIOGRAPHY. (I) Theiler, A.: Gall-Sickness in South Africa (Anaplasmosis of Cattle),

"Journal of Comparative Pathology and Therapeutics," Vol. XXII!., IPart 2.

(2) Bruce, D.: "Report of Sleeping Sickness Commission," No. 10, 1910, lpp. 100-101.

(3) Jowett, W.: Some Observations on the Subject of Marginal Points, ." Journal of Comparative Pathology and Therapeutics," Vol. XXIV., Part I,

pp·40-44· (4) Schafer, E. A.: "Quain's Elements of Anatomy," Vol. II., Part I,

-19 12, p. 369. (5) Balfour, A.: "Fourth Report of the Wellcome Tropical Research

Laboratories," Vol. A., Medical, 19II, pp. 120-121 and 345-347. (6) Sweet, Gilruth, and Dodd: "Parasitology," Vol. IV., No. I, pp. 1-6. (7) Spreull, J.: Marginal Points, or aNew Intracorpuscular Parasite in

the Blood of Cattle in South Africa. "Journal of Comparative Pathology _and Therapeutics," Vol. XXI!., Part 4, pp. 354-357.

(8) Sieber: Anaplasmosis, Abstract, "Journal of Comparative Pathology and Therapeutics," Vol. XXIV., Part 2, p. 146.

(9) Bevan, E. W.: Anaplasmosis of Cattle, "Veterinary Journal," No. 44, July 1912. Ibid.: Anaplasmosis of Sheep, "Veterinary Journal."

(10) Hutyra und Marek: "Spezielle Pathologie und Therapie der Haus­-tiere," Third Edition, Vol. 1., pp. 762 and 782.

(I I) Goliard and Goodall: "The Blood," I 9 I 2.