PROTOZOA 391 



Nuttall, Pantham and Porter r> observed the movements 

 of this parasite within the blocd corpuscles. The following is 

 taken from their conclusions on the "omnibus hypothesis," 

 which is based on the assumption that the invasion of the red 

 blood corpuscles may take place in the spleen or bone marrow 

 and that the corpuscles act chiefly as vehicles for parasites 

 destined solely to gain an entry into ticks for the purpose of 

 undergoing further development: "The corpuscles are pene- 

 trated by parasites as the blood circulates through the internal 

 organs; the parasites multiply in these organs but not in the 

 corpuscles. As the disease progresses more and more protozoal 

 passengers board the transporting vehicles, the corpuscles. 

 This hypothesis offers an explanation of the fact that (1) the 

 disease is not communicable by blood inoculation ; (2) that the 

 percentage of infected corpuscles not only' increases steadily, 

 but that the percentage of corpuscles containing many para- 

 sites grows as the disease advances; (3) that the parasites do 

 not persist in the blood after recovery. It is, of course, con- 

 ceivable that intracorpuscular multiplication may take place; 

 if it occurs the process must be very slow. 



"The assumption appears justified that the parasites ob- 

 tain nutriment from the corpuscles they inhabit. The dis- 

 covery recently made by Meyer T that East Coast Fever may 

 be communicated by transplantation of the affected spleen or 

 pieces of that organ goes to support the hypothesis here ad- 

 vanced, for doubtless the transplanted splenic tissue lived on 

 for a time in the peritoneal cavity of the experimental animals 

 and served as a nidus wherein the parasites continued to mul- 

 tiply. Meyer's experiments demonstrate that the spleen, and 

 possibly other internal organs, serve as the primary seats of 

 the invasion of the blood corpuscles by the parasites. 



' ' Summarizing our observations on the living parasite, we 

 would state that they show active movements within the cor- 



6 Nuttall, Fantham and Porter. Parasitology, Vol. II (1909) p. 

 325. 



7 Meyer. Jour. Comp. Path, and Therap., Vol. XXII, p. 213. 



