L YMPHOC YTOZO ON PA LLID UM 

 DESCRIPTION OF PLATE III. 



Fig. i. — Free amoeboid forms found by the jelly method of chancres, glands, 

 condylomata, and sores of syphilitics. Each contains chromatin. 



Fig. 2. -A small amceba included within the cytoplasm of a lymphocyte. 



Fig. 3. — The chromatin of the ced-inclusion becomes surrounded by a definite cell- 

 wall, and divides into three circular masses, each containing a ceniral dot. 



FlG. 4.— Two parasites included in a lymphocyte. One possesses three deeply 

 staining dots, the other a dot and a rod ; the former is an early stage of the development 

 of the female and asexual form, the latter is an early phase of the development of the 

 male form. 



Development of the Female and Asexual Elements 



Fig. 5. — This cell, from a chancre, contains two female and asexual parasites. In 

 one the chromatin is in the act of division ; in the other it has already divided. 



Fig. 6. — A parasite found in a lymphocyte of the blood squeezed from a syphilitic 

 papule. Within the parasite there are eleven separate chromatin masses, one of which is in 

 the act of dividing. Each chromatin mass contains a de ply staining dot — a feature of 

 these parasites. 



Figs. 7, 8, 9, 10 — Free amoeboid forms derived from the bursting of forms like 

 fig. 6. On the jelly they are highly amoeboid. Each contains a nucleus and granules, 

 some contain vacuoles, and all hive a central intranuclear dot. These represent, according 

 to their close analogy to Lymphocytozoon cobayut, the female and asexual forms. 



Development of the Male Elements 



Fig. 11. — The chromatin rod and dot in fig. 4. have multiplied within the cell- 

 inclusion into three rods. The cell is irom a chancre. 



Fig. 12. — A mononuclear cell from a chancre containing three parasites. Two show 

 the formation of the microgametes within the microgametocyte ; the third is an early phase. 

 The pink-coloured sausage-shaped body is probably a diffusi-in vacuole; it contains no 

 structure. 



FlG. 13. — An epithelial cell from a syphilitic gland. It contains a large parasite in 

 which there is a bunch of microgametes. These are radiating from a common centre or 

 hub like the spokes of a wheel. Some of these gametes have the same optical appearance 

 as Spirochata pallida, but only the chromatin of the spirochetes is stained. From the 

 analogy of Lymphocytozoon cobayce the hub is formed from the rod pictured in fig. 11. 



Fig. 14. — A large mononuclear cell found in the finger-blood of a case of secondary 

 (macular) syphilis. It shows the mode of the formation of the microgametes within the 

 microgametocyte. The lymphocyte was alive on the jelly, as is demonstrated by its 

 pseudopodia, and the parasitic inclusion burst while under examination ; the spirochetes 

 were ejected into the plasma. Note how the nucleus of the host cell is squeezed. 



Development of the Conjugatkd Forms 



Figs. 15, 16, 17, 18. — Copper-coloured holies found in the chancres, glands, sores, and 

 peripheral blood of syphilitics. They contain numbers of deeply staining granules. By 

 analogy with Lymphocylozoon cobayie ihese represent the conjugated fwrms, but they are 

 generally found free and not included within the cells. 



Fig. 19. — A cell-inclusion, stained by Leishman's stain, from a syphilitic gland 

 found by Colonel Jennings. The chromatin granules are very similar to those of the 

 conjugated forms of Lymphocytozoon cohayec. If, as is the case of the guinea-pig parasite, 

 these give rise to buds containing the granules, the cycles of schizogony and sporogony 

 of this parasite are complete. With the exception of fig. 19, all the drawings are as seen on 

 the jellies. They are by E. H. Ross. 



The parasites seen in rabbit syphilis {Lymphocytozoon lepofis) are smaller than the 

 above, otherwise they are identical. 



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