292 H. M. WOODCOCK. 



kinetonucleus is some distance from the extremity. (V.) liosts : Myot is 

 muriiius, and Vespertilio kuhli, Algeria and Tunis. In certain of 

 the Vespertilio kuhli examined much larger forms were seen, 25 — 30 /t 

 by 6 /i, for which the name T. vespertilionis is proposed provisionally. 

 The possibility is recognised, however, that these forms may be individuals 

 about to divide [or perhaps sexual (female) individuals. i^]. Petrie (83) 

 has recently observed Trypanosomes in Pipistrellus pipistrellus, in 

 Hertfordshire, which he thinks may have been T. nicolleorum, although 

 they were shorter (apparently only about 16 /x long). 



T. dionisii, Bettencourt and Franca, 1905. Full dimensions not 

 given; length of free flagellum 6'5ju. Kinetonucleus quite at anterior 

 extremity. Hosts: Vesperugo pipistrellus, V. serotinus, and V. 

 nattereri, Portugal. 



B. Pathogenic forms. — We come next to the so-called pathogenic 

 group. These parasites have been "successfully" inoculated into many 

 and various Mammalia, which cannot, however, in the majority of cases be 

 regarded as natural, tolerant hosts. In dealing with these disease-causing 

 forms, it is obvious that the more narrowly the original source of the para- 

 site is defined the closer do we get to the true host or hosts. Similarly with 

 the Invertebrate hosts, it is sometimes rather difficult to be certain which 

 is the natural one for the species concerned, for experiment has shown 

 that a biting-fly, other, in all probability than the true host, can, as it were, 

 accidentally convey the parasites, if, after feeding on an infected animal, 

 it is allowed to bite a fresh one within a limited time. One helpful factor 

 in this determination is the coincidence of the zone of a particular Insect' 

 with that of any disease. 



T. brucii, Plimmer and Bradford, 1899. (Syn. T. brucei. Buff, and 

 Sch., followed by L. and M. and others.) Length 28-30 /t, breadth U-2h fi. 

 The anterior end is usually bluntly rounded or truncated (figs. 42 b, 44). 

 The cytoplasm often contains in the posterior half large deeply-staining 

 granules. Hosts: (V.) probably Antilopida3, such as Catoblepas gnu, 

 Strepsiceros capensis ("Koodoo"), and Tragelaphus scriptus 

 sylvaticus (" Bushbuck"), perhaps also buffaloes; (I.) Glossina mor- 

 sitans and G. pallidipes, Tsetse-flies. The cause of Nagana or Tsetse- 

 fly disease in South and South-east Africa among cattle, horses, etc. Most 

 domestic animals are susceptible. 



Other trypanosomoses, moi'e or less allied to Nagana, and perhaps caused 



by different varieties or races of the same parasite, have been observed in 



German East Africa and Togoland among cattle, hoi'ses, and other animals. 



Again, the disease known as " Aino," which occurs in Somaliland among 



1 A very useful map showing the zones of distribution of the different 

 species of Glossina is given by Austen, E., Hep. S. S, Comm. Eoy. Soc, 

 6, p. 278, 1905. 



