84 - Trans. Acad. Sct. of St. Lowis 
each of the 1477 bred moths, and of the arrival and activities 
of each of the 1249 wild moths; thus the study comprises the 
individual records of 2726 moths. 
While the problem involved many real difficulties and compli- 
cations, yet the material held certain unusual advantages for 
such experimentation. These moths are easily handled, and have 
wings sufficiently large on which to paint distinguishing marks, 
so that accurate records may be kept of each individual. They 
require no food in the adult stage, so all adverse conditions aris- 
ing from improper food are eliminated. By breeding the speci- 
mens from cocoons, accurate data may be had as to the age of 
the moths, and the factor of age in influencing their responses. 
While this material came from Long Island, New York, three 
of the species, Samia cecropia, Telea polyphemus and Callosamia 
promethea, are natives of Missouri also. The fourth species, 
Platysamia cynthia, is not native of Missouri, but is abundant 
in the Atlantic States. Hence, in experimenting with the first 
three species, one had to contend with interference, sometimes 
favorable and sometimes troublesome, of the wild population 
hereabouts, but in handling the cynthias, we were certain that 
our imported stock constituted the entire population, although 
in some cases there was reason to believe that some of these 
moths responded slightly to the attraction of the females of the 
other species, and may thus have reduced the otherwise high 
percentage of returns. 
The experiments could not be carried on just as they were 
planned ; because of unexpected difficulties one could only take 
what material was at hand, quickly plan an experiment and 
execute it in the best way the conditions afforded. This factor 
may give the work a tone of not having been carefully planned. 
The difficulties were, of course, that often when one needed 
females, only males would emerge, and vice versa, and often 8 — 
shifting of the wind, a change in the weather, and urban crowds, 
caused a change in a contemplated experiment. Extensive work, 
attempted two years later,* for the purpose of getting records of 
five-mile flights outside the city had to be abandoned because of 
the depradations of birds. Screech-owls devoured the incoming — 
night fliers, and by day the sparrows, blue-jays and woodpeckers 
*At Kirkwood, Mo. 
