PART II. 
EXPERIMENTAL STUDIES ON ODOR, WIND AND LIGHT 
IN RELATION TO RHYTHMIC PERIODICITY 
IN SATURNIID MOTHS. 
INTRODUCTION. 
In part I of this paper, we have already seen how a tiny mass 
of flesh and blood ealled a Saturniid male braves the elements 
and overcomes nature’s obstacles for a distance up to three 
miles to reach another mite of flesh and blood, the female 
Saturniid. In the coming together of these two masses, space is 
annihilated, and we seem to get a combination which is rivaled 
only in the chemistry laboratory. I say ‘‘seem to get’’ advisedly, 
because these moths possess sense organs which surely must 
function in a way that is not analogous to anything in the 
chemistry laboratory. 
While to most organisms we accede five senses, in the case of 
the adult Saturniid moths we must eliminate the sense of taste. 
So here this organism traveling so actively toward its goal can 
be credited with possessing the olfactory, auditory, tactile and 
optical senses. Some or all of these four senses function, either 
in distant or proximate orientation. _ 
What is the vehicle of the stimulus? What do these four 
sense organs brush up against as this tiny organic mass shortens 
the space between itself and the object of its flight? The at- 
mosphere, and the vibrations which transmit light, sound and 
possibly other sensations of which we are not aware, since We 
have no organs to receive them. The atmospheric currents and 
gases, oxygen, nitrogen,* ete., are capable of bearing odors ; 
which ean be received by the olfactory organs. Vibrations 
transmit the light of the moon and stars, light of various de- 
grees of intensity from the sun, and in the city where the ex- 
periments were conducted, light from street lamps, houses and 
automobiles. These, presumably, can be perceived by the optic 
organs. Sound vibrations as a means of communication are 
*In the heart of a city, many other gases and impurities. 
