168 SUMMARY OF CURRENT RESEARCHES RELATING TO 



seems to indicate that we have here different methods of response to the 

 same stimulus. 



New Trypanosome from a Tick.* — A. Lafont describes Trypano- 

 soma hoylei sp. n. from a Eeduviid, Conorhinus rubrofasciatus, of 

 Mauritius. It is communicable to rats and mice. The new parasite 

 has considerable distinctness from other species, and is marked by 

 striking polymorphism, by the dimensions of its blepharoplast, and its 

 position relative to the nucleus in the adult form. 



Life-history of Leucocytogregarina musculi.t — G. Sangiorgi finds 

 that this parasite ( = Leucocytozoon musculi Porter) can pass through 

 all its stages (schizogony, gamogeny, metagamy) in the lung of the 

 mouse. By asexual multiphcation 22-36 merozoites are formed. Two 

 isogametes conjugate to form a gamete, which leads to the formation 

 of eight sporozoites. There is no change of host required. Healthy 

 animals are mechanically infected by the agency of Hsematopinus 

 spinosus. 



New Gregarine in Mid-gut of Bird-fleas.^— J. H. Ashworth and Th. 

 Eettie describe the structure and hfe-history of Steinina rotundata sp.n., 

 from the mid-gut of fleas- — Ceratophyllus styx- — from a sand-martin's 

 nest. It is near Steinina ovalis Leger and Duboscq, but the spores are 

 larger and less strongly inflated. In the younger trophozoites, the pro- 

 tomerite and deutomerite together usually form an oval or sub-spherical 

 mass, but later the organism becomes more or less pyriform. The adults 

 are solitary, except when association in pairs occurs preparatory to the 

 formation of gametes. If there be an ultra-cellular stage, it must be of 

 brief duration. The cysts are spherical, 110-185 />t in diameter, and 

 without sporoducts ; the spores are oval, 11-12 /x long, and about 7 /a 

 broad. 



Transmission of Leishmaniosis by Cultures.§— A. Yisentini finds 

 that guinea-pigs and rats possess natural immunity to a high degree 

 against the Leislimania of the Mediterranean basin in the flagellate 

 stage in cultures on blood-agar (method of Novy-McNeal-Nicolle). 



This immunity is exclusively of a phagocytic nature. The Protozoa 

 injected into the peritoneum become rapidly engulfed by the leucocytes, 

 the mononuclears exclusively, and undergo gradual and progressive 

 alterations, ending in their complete destruction. At the end of 1 to 

 \\ hours, after the injection of 2 c.cm. of a culture in full develop- 

 ment, free flagellates are no longer to be found in the serum, and after 

 two or three hours even the last vestiges of them are almost destroyed 

 in the protoplasm of the phagocytes. 



The Protozoa do not pass beyond the barrier of the peritoneum, and 

 do not find their way into the blood or the internal organs. These data 

 of observation receive full confirmation in the results of the cultures. 



* Ann. Inst. Pasteur, xxvi. (1912) pp. 893-922 (2 pis.). 



t Centralbl. Bakt. Parasitenk., liv. (1912) pp. 287-93 (1 pi). 



: Proc. R. Soc, Ixxxvi. (1912) pp. 31-8 (1 pi). 



§ Quart. Journ. Micr. Sci., Iviii. (1912) pp. 373-84 (1 pi.). 



