978 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



be expected, abundant h^matozoic embryos were found. In tlie same 

 region Prof. Danilewsky also observed within the corpuscles oval masses, 

 which divided by a process of (muriform) segmentation (hardly to be 

 described as sporulation) into a number of embryos. In other cases the 

 minute embryos were seen apart, evidently liberated from a ruptured 

 cytocyst. 



According to the author, each corpuscle containing a haemogregarine 

 parasite, has received the latter from a hsematoblast. The hsematoblast 

 may itself have engulfed a germ, or may have received it from a leucocyte. 



Germs originating from a spore-forming Gregarine in some part of the 

 alimentary canal or urino-genital ducts may readily become included in 

 the leucocytes. In the interior of the latter the germ undergoes a solitary 

 and progressive development, while the containing cell is transformed into 

 a blood-corpuscle. In this intracellular life the parasite passes through 

 the stages which in the normal history of Gregarines are known as primitive 

 germ, pseudonavicella, falciform body, and mobile adult. In contrast to 

 the usual history the hgemogregarine developes within the corpuscle from 

 an almost imperceptible germ to maximum size, and that at the expense of 

 extrinsic nutritive material. There is a certain parallelism, not without 

 exceptions however, between the blood-corpuscle and the included h^mo- 

 gregarine. The presence of the parasite does not appear to affect the 

 vitality of the developing blood-corpuscle. 



As to the mode of introduction into the tortoise. Prof. Danilewsky is 

 inclined to regard the alimentary canal as the most probable entrance, and 

 there is no doubt that in the insects, myriopods, &c., eaten as food, there is 

 an abundant source of supply for Gregarinoid parasites. 



New Parasite of the Pock-process belonging to the Sporozoa.* — 



Dr. L. Pfeiffer has found a coccidia-like parasite which, in company with 

 fungi and bacteria, lives in the pocks of various mammals and of man, and 

 passes its first stages in the epithelial cells of the rete Malpighii : in this 

 respect it would agree with the coccidia inhabiting epithelia (e. g. Coccidium 

 oviforme Leuck.). The author found it very frequently in sections through 

 the rete, partly in layers, partly within the epithelial cells, which were 

 swollen up by the growth of the spherical parasites and finally destroyed. 

 The smallest examples are 0*009 mm. large, and show a bright nuclear-like 

 spot about 0*005 mm. in size. Like Coccidia, this Monocystis epithelialis, 

 as the author calls it, forms a thick sheath, the original capsule is thrown 

 off and a new one formed. Several examples are rarely found in one cyst. 

 After incapsulation sporulation begins. The spores which are found in 

 quantity in the lymph appear to pass directly into amoeboid, slightly mobile 

 embryonic bodies. The author regards the transparent blood-corpuscle-like 

 discs as the young condition of the parasite, and is disposed to think that 

 the entrance into the epithelial cells is perhaps not necessary for its deve- 

 lopment, as the parasites are found free in the protoplasm of the vesicles, 

 and as it is possible to breed and propagate them in the artificial media up 

 to the third generation. 



* Correspond eaz-Blatter allg. arztl. Vereins v. Thiiringen, 1887, No. 2, 12 pp. 

 (2 pis.). 



