H. Seidelin 
227 
possible that the vacuoles observed in various trypanosomes, between 
the two nuclei, may be of a similar nature. For the general physiology 
and biology of the protozoa the occurrence of such a process, although 
it may be an exceptional one, is obviously of considerable interest. 
In the case of trypanosomes, the ordinary mode of nutrition is believed 
to be that of diffusion through the superficial membrane, but the 
observations here recorded show a certain resemblance to the con¬ 
ditions obtaining in the case of amoebae and many other protozoa. 
The occasional ingestion of such large elements as erythrocytes suggests 
that the parasites may perhaps also ingest smaller particles, a process 
which it would be difficult to observe. The individuals concerned in 
the digestion of erythrocytes show as a rule somewhat prominent 
(volutin) granules in their protoplasm, but it is not clear whether there 
is any relationship between the two phenomena. 
I am indebted to Dr A. Connal, Director of the Yaba Institute, 
for the facilities afforded me. 
EXPLANATION OF PLATE XVIII. 
Giemsa stain. Zeiss’ apochr. imm. 3 mm., comp. oc. 12. Abbe’s 
drawing apparatus. Magnification 1300. 
Figs. 1-3. Ingestion of erythrocytes by trypanosomc.s. 
Figs. 4-11. Various stages of digestion. 
Fig. 12. Trypanosome containing vacuole. 
