270 DIFFERENCES IN ANAEROB. FUNCTIONS 



aerobic coiulitioiis and between 9.5 and 10,5 under an- 

 aei-obic conditions. The internal rll of Opulina ranarum, 

 another frog parasite, seems to be even lower, as the 

 above authors (1927) deduce from observations by Becker 

 (1926) that the protoplasm of Opalina reduces Janus 

 Green, a dye having an electrode potential below that of 

 indigo tine monosulphouate. They then conclude : "It 

 seems that in the facultative anaerobe the oxidation- 

 reduction potential can be adjusted to the environment, 

 while in the strict aerobe changes in the environment 

 which would lead to such an alteration in the rH bring 

 about death." The first purt of this statement is con- 

 firmed by the observations of Nassonov (1932) that the 

 internal rH of the Opliryoscolecidae, typical anaerobic 

 ciliates of the rumen of herbivores, changes readily with 

 that of the surroundings. But the second part has not 

 been corroborated. 



Ssinitza's (1936) findings are in disagreement with 

 those of most other workers. According to her the rH of 

 the blood of Chironomns plumosus was lowered during 

 anaerobiosis, while that of Psectrocladius hrevicalcar 

 was slightly raised. This latter larva, however, resists 

 asphyxiation much better than the former. 



The majority of investigators, on the contrary, found 

 that in normally aerobic invertebrates (amoebae, re- 

 productive cells of echinoderms, tissues and blood of 

 snails and insects) the rH is lowered when oxygen is 

 excluded from the surroundings. The rH in aerobic 

 conditions is listed as lying between about 12 and 20, and 

 in anaerobic conditions between about 5 and 9. For 

 details the following papers should be consulted: Cohen, 

 Chambers and Reznikoff, 1928; Chambers, Pollack and 

 Cohen, 1929; Aubel and Levy, 1929, 1929a, 1930, 1930a; 

 Chambers, Cohen and Pollack, 1932; Alexandrov, 1932; 

 Machlis and Green, 1933 ; Cohen and Chen, 1933 ; Cham- 



