22 Trans. Acad. Sci. of St. Louis. 
possible to make more extended observations. The 
imagines were placed under the same climatic conditions 
and were given an opportunity to mate as soon as possible 
after hatching. The material proved to be good for just 
such observations, as all the matured individuals of this 
family have rudimentary mouth parts, and the Cecropia 
moths take no food. 
The observations and notes were never made at greater 
intervals than six hours; the last notes were made each 
day near midnight, the first in the morning about six, 
and during the day notes were made at intervals of about 
three hours. The time upon which the tables are based 
is the time when the notes were made, not the time when 
the act (mating, hatching, dying, etc.) may have occurred. 
This method is not mathematically exact, since it is impos- 
sible to be present at the precise moment when the insects 
mate or hatch or die. I think, however, that my figures 
are as exact as could possibly be obtained. The observa- 
tions extended from the time when the first pair was seen 
in copulo, May 16, 1909, until the death of the last male 
on June 22, 1909. 
It gives me great pleasure to here acknowledge my in- 
debtedness to Professor A. C. Eycleshymer of St. Louis 
University and Professor J. F. Abbott of Washington 
University for valuable suggestions in the preparation 
of this paper. 
II. Osservations on Lire Cycie. 
1. DURATION OF LIFE OF MALE. 
(a) The duration of life of male from hatching until 
death. 
Notes derived from observations in six instances. In 
the following tables the designations are for each copu- 
lating pair: 
KNOWN AS DAYS HOURS 
A 10a 11 5:30 
A 8 10 23:30 
Al4 10 4 
A 10 9 17 
A 12 9 16 
A 15 8 14:40 
