568 



William Reiff 



The normal length of life for the species of Actias and the more 

 closely allied Saturniids averages about 7 or 8 days. In the experi- 

 ments above described this normal period of life was represented 

 by the period in which the blood of the insect could circulate 

 unhindered by the low temperature, and coincided with the days 

 on which the temperature rose above 0° C. If from the total 

 length of life of the specimens on which I experimented we sub- 

 tract the time of the anabiotic condition, we obtain for the female 

 6 and for the male 5^ days of normal life. Neither of the speci- 

 mens reached the normal mean of 7 to 8 days. Instead of regard- 

 ing this condition as being due to the individual constitution of 

 the specimens, I believe it is more correct to attribute the shorten- 

 ing by one to two days to the anabiotic state. According to the 

 work of Bachmetjew cited above, this investigator established that 

 the insect juices do not completely congeal till a temperature of 



— 4.5°C. is reached, whereas 88 per cent of the juices congeal at 



— 3° C. and 97 per cent at — 4°C. Since in my experiments the 

 minus temperatures varied between 3° C. and 6° C. there must 

 have been periods when small portions of the juices (up to 12 

 per cent) were not congealed. At such times metabolism, al- 

 though of a very feeble sort, could occur in the animal and this 

 would not have taken place, if, during the anabiotic condition, the 

 temperature had remained constantly at —4.5° C. In such a 

 case metabolism could have gone on only before and after it had 

 been in the anabiotic condition, and certainly both moths would 



