40 THE JOURNAL OP^ THE 



the larvae had white instead of yellow tufts, with the excep- 

 tion of one, which I put in a box by itself the better to 

 observe it. On August 15 this one moulted, appearing with 

 white tufts, and pupated August 20. The others pupated 

 from time to time between August 14 and August 27. On 

 September 2, I found some larvse with yellow tufts on a 

 rose-bush, and put them in a box b}^ themselves. By the 

 next morning one of them had pupated, another moulted 

 during the next day and appeared with white tufts. 



In the course of my experiments I observed larvre in the 

 act of moultino; on several occasions. Thev fastened their 

 tails to the box and soon the skin which covers the head 

 separated, and was then easily pushed off. The remaining 

 portion split for a part of the way along the back, and the 

 caterpillar by working its bod}^ from side to side, and appar- 

 ently rubbing it against the box, gradually pushed the old 

 skin back till freed from it. In some instances the cater- 

 pillar would bend its head under its body and rub it on the 

 box to get off the old skin. Once the old skin split on the 

 under side. In all cases the larvae seemed exceedingly 

 exhausted by the process, but after resting commenced feed- 



nisc a gram. 



Some of the larvae hatched from eggs laid in the box, 

 chano-ed back from the white to the vellow tufts before 

 pupating. Some that pupated about August 14 produced 

 moths September 5. The one referred to as pupating 

 August 20 produced a female. From the eggs laid in the 

 box about one male to ^nq females hatched, but in the 

 earlier broods the proportion of males was greater. It 

 would seem that sex had nothing to do with the changes 

 in color. 



I noticed that the yellow stripes along the sides became 

 whitish with a slight tinge of green before pupating. On 



