Rau—O bservations on Samia Cecropia, Linn. 37 
injury and perhaps loss of vitality, they were overtaken 
by death, regardless of whether or not the propagation of 
the species had been assured to the fullest extent. The 
duration of life does not seem to be regulated by the needs 
of the species, but is controlled by some unknown internal 
force. 
V. SumMMARY. 
1. The 68 good cocoons hatched 43 males and 205 
females.’ 
2. The species is monagamous. 
3. The Cecropia moths take no food or water. 
4. The shortest entire duration of life of male was 8 
days 14 hours and 40 minutes; the longest was 11 days 5 
hours and 30 minutes. The average for six cases was 10 
days 1 hour and 26 2/3 minutes. 
5. The longest duration of life of male from copula- 
tion until death was 13 days 1 hour and 30 minutes; the 
shortest was 7 days and 30 minutes. The average dura- 
tion was 9 days 17 hours and 39 minutes. 
6. The greatest duration of life of male from termina- 
tion of copulation until death, which can be no other than 
useless life, was 12 days 1 hour and 30 minutes. The 
shortest useless life was 6 days and 1 hour. The average 
duration for the ten instances was 9 days and 42 minutes. 
7. The greatest length of time that any male survived 
its mate was 8 days and 11 hours; the shortest survival 
was 12 hours and 30 minutes. The average length of 
time that the ten males survived their mates was 3 days 
18 hours and 38 minutes. 
8. The longest duration of entire fertilized female life 
was 9 days 19 hours and 30 minutes. The shortest was 
8 The number of males was also greater in a collection at Washington 
University. Thirty-five individuals had hatched in the spring of 1909, 
twenty-two being males and thirteen females. 
