122 ISABEL M CRACKEN. 



Since, therefore, the wings are present and are under perfect 

 muscular and nervous control, what is apparently missing in the 

 normal moth is the flight " instinct," or the disposition to set in 

 motion those reflexes that make for flight. 



A study of the habits of the male silkworm moth has been 

 made, therefore, with special reference to the flight function and 

 some interesting suggestive conditions have been observed. 



As previously stated, the mating instinct is strong in the young 

 male. It is at once aroused if a female is near and the numerous 

 reflexes that effect mating are initiated. Upon leaving its cocoon, 

 under ordinary conditions, the male seeks the near-by female. 

 After several hours in copula separation takes place. The female 

 then begins to oviposit, and the male seeks another female and 

 thus passes from female to female throughout the few days of its 

 existence. Thus we may say that the mating instinct once 

 aroused is the dominating and controlling instinct. In the ab- 

 sence of the female the male behaves somewhat differently. If 

 a young male moth is isolated in a closed box and in a room 

 with no females present, it remains for several days in a perfectly 

 passive condition, scarcely moving. On the fourth or fifth day 

 the moth begins to flutter wildly about within the box, and upon 

 removal of the cover soars into the air, circling about and sus- 

 taining itself upon the wing for from thirty seconds to several 

 minutes. It comes to rest seemingly from fatigue and may, after 

 a few seconds, during which the wings are vigorously fluttering, 

 again take flight for a few minutes finally coming to rest again to 

 remain wherever chance may find it until death ensues. 



Having by chance observed this behavior in several male 

 moths, I selected, at the height of the breeding season, a large 

 number of males as they issued from their cocoons and placed 

 them in a large well-hghted room by themselves, some individu- 

 ally within closed boxes and others exposed each by itself on a 

 small tray. In many cases the moth remained perfectly quiet 

 for several days, then wandered about with a fluttering of the 

 wings, finally coming to rest and remaining in a quiet condition 

 until death. By far the greater number, about seventy-five out 

 of one hundred, behaved as in the cases previously noted. They 

 fluttered about vigorously on the fourth to the eighth days and 

 then soared upward. 



