146 ENTOMOLOGICAL NEWS [April, 'l2 



This was in the early part of the winter of 1909, at Ames, 

 Iowa, where some extensive experiments on this species were 

 being carried out. 



The following detailed account of the process and the subse- 

 quent actions of the newly emerged nymph are given almost 

 word for word as I have them from the records taken at the 

 time. 



At 11.50 A. ]\I. on December nth, I came into the labora- 

 tory as usual to take notes on the breeding cells. These cells 

 were very small glass stender dishes. Each was small enough 

 to be placed on the stage of the microscope, and each contained 

 a single, isolated individual upon some very small, one-leaved 

 plant. The larva in cell A 25 was observed along with the oth- 

 ers, and at first I saw that the larva had fixed itself for a molt. 

 But to my surprise as I examined it more carefully, I thought 

 I saw it move slightly. At once I took my hands ofif the micro- 

 scope to be sure that this apparent motion was not due to rny 

 own movements. The larva was now seen clearly to move. Its 

 body was moved back and forth and sideways, but the legs 

 were kept still. Suddenly in a single instant the skin of the old 

 larva burst all the way across the body just behind the scapu- 

 lar groove on the dorsal surface. In another instant some of 

 the dorsal bristles of the cephalo-thorax were released as if 

 they were springs, and projected in almost their normal posi- 

 tion. At the same time the eyes of the emerging nymph burst 

 into view. 



Now began a series of side motions and of backward strains. 

 The hindmost larval legs were used, being extended laterally 

 and slightly anteriorly. At the same time the muscles of the 

 body gave it a wriggling motion. These motions continued for 

 about one minute when the whole anterior part of the new 

 nymph began to be drawn out of the anterior part of the old 

 larval skin. This motion was at first rather slow until the an- 

 terior legs were released from their old sheath, when all of a 

 sudden the whole nymph pulled loose from the anterior part of 

 the old skin. 



The now half emerged nymph, having thus shed its coat, so 



