200 AXAEUOIilC MJ'JTAliOLLSM 



servation that an acidification takes place in the sugar- 

 containing sohition in which trypanosomes are kept; Gei- 

 ger, Kligier and Comaroff from the decrease of the alka- 

 line reserve of the same culture media. That these ob- 

 servations are inconclusive has been shown by von Brand, 

 Regendanz and Weise (1932) and by Eeiner, Smythe 

 and Pedlow (1936) who demonstrated, by direct deter- 

 mination, that lactic acid does not occur in significant 

 amounts among the end products of the anaerobic metab- 

 olism of pathogenic trypanosomes. The small traces of 

 lactic acid that were found by Reiner, Smythe and Pedlow 

 were possibly not due to the trypanosomes but to leuco- 

 cytes which can hardly be separated completely from the 

 flagellates when the latter are being prepared for the ex- 

 periments. 



Lwoff (1934) observed that some trypanosomidae lib- 

 erate carbon dioxide from bicarbonate under anaerobic 

 conditions. With Strigomonas oncopelti, 88 c.mm. of car- 

 bon dioxide were liberated per milligram dry weight per 

 hour; with Strigomonas fasciculata, 65 c.mm. and with 

 Leptomonas ctenocepJiali, 5 c.mm. He concludes from his 

 manometric determinations that the acid which unques- 

 tionably was formed is lactic acid. Though there is no 

 evidence directly contradicting this view, a confirmation 

 by direct chemical analysis is very desirable, since, as 

 has been explained above, lactic acid is certainly no com- 

 mon end product in this group of organisms. 



Dausend (1931) follows a different line of reasoning 

 in the case of Tubifex. This w^orm metabolizes large 

 amounts of glycogen during anaerobiosis ; and if, after 

 having been kept for 23 hours under anoxic conditions, it 

 is transferred for 4 to 6 hours to oxygenated surround- 

 ings, about 50 per cent of the lost glycogen is resynthe- 

 sized. It is a well-established fact that, under similar 

 conditions, an isolated vertebrate muscle also reconverts 

 4/5 of the lactic acid produced into glycogen. Dausend 



