460 
a few rounded forms of trypanosomes can be found in a cubic 
millimetre of peripheral blood. 
Biot (1910) writes of the ‘revivifying action’ of physiological 
salt solution on trypanosomes (T. lewis't ), especially in fluid from 
the liver of a rat dead six and a half days (kept in the cold, 
unopened). Biot does not explain the phenomenon. However, it is 
capable of explanation, for in the liver latent bodies of 
trypanosomes are present, which, under the relatively favourable 
environment of isotonic salt solution, flagellate and become typical 
trypanosomes. 
In the treatment of trypanosomiasis by drugs, careful note must 
be taken of the occurrence of rounded, non-flagellate or latent forms 
of the parasite. A drug needs to be found which will either prevent 
the formation of rounded (latent) stages or disintegrate those latent 
bodies already formed. In this connection the work of B. Moore. 
Xicrenstein, and Todd* on the combined use of salts of mercury 
and arsenic should be considered. 
NOTE ON THE DEGENERATION OF TRYPANOSOMES 
All flagellate trypanosomes do not become rounded and form 
latent, non-flagellate bodies, but some of them degenerate and die. 
I he degeneration may take v arious forms —some become (a) 
somewhat irregular and almost amoeboid with pale-staining 
cytoplasm and vacuoles (figs. 44, 45), others (ft) exhibit 
chromatolysis, wherein the nucleus becomes poor in chromatin and 
chromatoid granules occur in the cytoplasm (figs. 46-49)1 w ^ e 
others (7) exhibit marked vacuolation (fig. 50). Such degenerating 
lorms may be seen in various internal organs of the host, such as 
the lungs and spleen, especially during the period of formation ot 
latent bodies. 
It is also very probable that some of the latent bodies themselves 
die and do not flagellate, for some shrunken latent bodies, with 
undifferentiated contents, can be seen in the spleen. 
\nit. 1 ro P- »nd P.irasitoL '1907;. Vol. I. pp. 275-284. 
