272 ^Journal of Comparative Neurology and Psychology, 



These were isolated in individual boxes to avoid the possibility 

 of stimulation by contact. The average length of life in the former 

 was fourteen days, the average length of life in the latter was thir- 

 teen days, showing thus no great deviation from that of the normal 

 insect. No unmated moth oviposited at all. Amongst the forty 

 mated moths but three produced any eggs, one of these producing 

 one, one producing four, and one producing six eggs. In the 

 latter case the eggs were produced immediately after the moth had 

 been lifted by the wings, consequently after having been submitted 

 to stimulation to that extent. In the other two cases no stimu- 

 lation was known to have taken place. From the fact that such a 

 large number of unstimulated moths failed to produce any eggs 

 after decapitation, and from later results with stimulated insects, 

 it seems that spontaneous egg production under this condition is 

 exceedingly rare. 



Furthermore, in neither mated nor unmated insect was there any 

 extension of the alluring glands, nor was any stimulation such as 

 pressure, rubbing of the abdomen by the male, etc., sufficient to 

 induce an extension of these glands. Whether this was due prima- 

 rily to the fact that these were deprived of their innervating center 

 through loss of the head (the brain) or whether the loss of antennae 

 alone would have brought about the same result, was not deter- 

 mined. Probably the nature of the stimulus was also inadequate. 

 The behavior of the alluring glands demands special consideration 

 and was not taken up in this investigation. 



In Series 7 and 8 the moths (about twenty in each case) were 

 either mated or left unmated, and permitted to oviposit normally 

 a small group of eggs. Then the head was. removed by a sudden 

 snip with a sharp scissors. In no case did ovipositing continue, 

 nor were any more eggs produced throughout the life of the insect, 

 although moths in the series lived for an average of twelve days. 



In Series 9 the moths were first decapitated; later, although 

 there had been no extension of the alluring glands, there was 

 apparently no difficulty in the way of mating. In every case 

 (about twenty females were observed), the males that were walking 

 about upon the table, vibrating their wings in the air, found the 

 headless females and upon contact of the two bodies and after a 

 little manoeuvering on the part of the male, by way of circling 

 about and rubbing the body of the female partly for the purpose 

 of orientation, mating invariably took place without difficulty. 



