440 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Trypanosoma brucei.*— J. R. Bradford and H. G. Plimmer describe 

 the adult form of this organism found in Nagana or Tse-tse fly disease, its 

 multiplication by longitudinal division and from a plasmodial mass by 

 detachment of buds, its conjugation, its " amoeboid " and " plasmodial " 

 forms, and its " micronucleus " (" blepharoplast," " nucleolus," " centro- 

 some," &c. of other authors) which seems to come off from the macro- 

 nucleus and which fuses with the corresponding body in another 

 individual. The " micronucleus " has tbis in favour of its beins a 

 centrosome that it nearly always divides before the macronucleus does 

 in the longitudinal division. 



The authors also discuss the distribution of the parasite, its variations 

 in different animals, and their resistance to it. The noticeable differences 

 between it and the Trypanosoma lewisi found in sewer rats are noted. 



The probable sequence of tbe life-history is: — (1) longitudinal 

 division, which is very common, seen more or less in the blood of all 

 the organisms examined ; (2) conjugation, the essential of which is the 

 fusion of the micronuclei of the conjugates, and (3) the fusion of the 

 adult forms in " tangles " or plasmodia which give off flagellated amoeboid 

 forms from the margin. 



New Trypanosoma.! — A. Laveran discusses Trypanosoma theileri 

 sp. n., called after its discoverer Theiler, — a veterinarian in Pretoria. 

 It seems a specific parasite of cattle, and injections into horse, dog, 

 rabbit, &c. proved ineffective The disease induced in cattle is a per- 

 nicious anaemia with or without fever, and with some striking features, 

 such as the rapid destruction of red blood-corpuscles. Laveran points 

 out that the number of species of Trypanosoma is rapidly mounting up. 



Terminology for Various Stages of the Malaria Parasite.! — 

 E. Ray Lankester proposes a clearer terminology than that in vogue for 

 describing the stages in the life-history of the malaria parasite and 

 similar forms. The life-cycle may be written as below, the sign x 

 being used to indicate fissile multiplication, -f- to indicate fusion, and 

 >- to indicate merely continuity. 



Exotospores 

 X and spore residues 

 in cyst 



Free 



-> exotospore 



Amoebula 



Spore-mother-cells 



Spore-cyst 



_Egg- 

 cell 



Female 

 crescent 



Eiihsemospores 



Amcebulae 



Vermicide 



Embryo-cell 

 (zygote) 



+ 



Spermatozoa x 



and sperm 

 residual sphere 



Male crescent 



* Quart. Journ. Micr. Sci., xlv. (1902) pp. 449-~l (2 pis.), 

 t Comptes Rendus, exxxiv. (1902) pp. 512-4. 

 X Proc. Roy. Soc. London, lxx. (1902) pp. 74-9. 



