so UBCES OF ENERGY IN ANAEROBIOSIS 193 



disappear from the Purascaris egg when it is kept in an 

 atmosphere free from oxygen. In adults of As<caris lum- 

 hricoides, in any event, no fat is consumed during anaero- 

 bic periods (Weinland, 1901; von Brand, 1934a) and 

 Faure-Fremiet (1913) even thinks that the fat content 

 of anaerobically kept Parascaris eggs increases. 



Barnes and Grove (1916) exposed larvae of the insect 

 Attagenus undulatus to an atmosphere of reduced oxy- 

 gen content by endosing them for a period of 5 days in 

 very small containers where the oxygen supply was 

 clearly insufficient to allow a purely aerobic life. The 

 amount of fat decreased from 28.7 to 26.3 per cent of the 

 dry weight and the authors concluded that the fat had 

 been utilized for energy production through anaerobic 

 processes. This conclusion is obviously not convincing. 

 The fat could have been used up during the initial pe- 

 riod when oxygen was still present in larger quantities, 

 and substances, such as glycogen, may have been metab- 

 olized later. 



Kozansikov (1935) found that the fat content of the 

 larvae of Pyrausta nuhilalis, during diai^ause, decreased 

 markedly when the animals were immersed in water at 

 25° C for 3 days. But this environment can certainly not 

 be regarded as wholly free from oxygen. 



Gilmour (1941) states that, in Tenebrio molitor larvae, 

 an anaerobic fat consumption of 4.5 mg. per g. fresh 

 weight per hour was observed in one series of his experi- 

 ments as compared to 0.18 mg. under aerobic conditions. 

 He writes further ''. . .in another set of experiments 

 (four in this case) variation was such that it was not pos- 

 sible to demonstrate a significant difference in fat con- 

 tent between a control series of insects and a similar se- 

 ries analyzed after anaerobiosis and recovery. If exact 

 quantitative data on the anaerobic processes are to be 

 obtained it will be necessary to have a stock of insects of 



