I20 



PROTOZOA 



fever recently recognised on the West Coast has been found to be 

 the early stage of the sleeping-sickness, that well-known and most 

 deadly epidemic of Tropical Africa, Through the researches of 

 Castellani, Nabarro, and especially Colonel and Mrs. Bruce, we know 

 now that the parasite T. gambiense is transferred by an inter- 

 mediate host, a kind of Tsetse Fly (Glossina palpalis). Schaudinn's 

 full study of a parasite of the blood corpuscles of the Owl has 

 shown that while in its intracorpuscular state it resembles 

 closely the malarial parasites in behaviour, and in its schizogenic 

 multiplication, so that it was considered an Acystosporidian, 



under the name of 

 Halter idium, it is really 

 a Trypanosoma ; 1 for 

 the accomplishment of 

 successful sexual re- 

 production it requires 

 transference to the 

 gut of a gnat (Gulex). 

 The germs may infect 

 the ovary, and give 

 the offspring of the 

 insect the innate 

 power of infecting 

 Owls. Thus a new 

 light is shed on the 

 origin of the Cocci- 

 diaceae, whose "blasts" 

 in the insect host re- 

 semble Trypanosoma, 

 in their morphology. 



The human Tick 

 fever of the Western 

 United States and the epizootic Texas fever. are known to be due 

 to blood parasites of the genus Piroplasma {Babesia), of w T hich 

 the free state is that of a Trypanosoma It appears certain that 

 Texas fever, though due to Tick bites, is not transferred directly 

 from one beast to another by the same Tick ; but the offspring 

 of a female Tick that has sucked an infected ox contains 

 Trypanosome germs, and will by their bites infect other animals. 

 1 Doubts still subsist as to the interpretation of Schaudinn's observations. 





Fig. 39. Morphology of Trypanosoma, a-f, Stages in 

 development of Trypanosoma noctuae from the 

 active zygote (" ookinete ") ; b, first division of 

 nucleus into larger (trophic) and smaller (kineto-) 

 nucleus ; c, d, division of smaller nucleus and its 

 transformations to form " blepharoplast " and myo- 

 neines ; /, adult Trypanosoma ; g, h, i, Treponema 

 zeemannii of Owl ; g, Trypanosome form ; h, 

 Spirochaeta form ; i, rosette aggregate. (After 

 Schaudinn.) 



