68 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



and the following present: Messrs. Barber, Burgess, Burke, 

 Busck, demons, Crawford, Gahan, Hall, Hammar, Heide- 

 mann, Hopkins, Howard. Hyslop, Kincaid, Knab, Kraus, 

 Phillips, Piper, Popenoe, Sanders, Sasscer, Schwarz, Smythe, 

 Viereck, and Webb, members, and Messrs. C. V. Burke, Cory, 

 McAtee, McCray, Middleton, Spillman, and Wall, visitors. 



The minutes of the last meeting were read and approved. 



The committee on the Van Horn resolutions reported and 

 the resolutions were ordered sent to the family. 



Messrs. H. L. Viereck, and H. S. Smith were elected active 

 members of the Society. 



-The following paper was read by the author : 



THE ROLE OF AIR IN THE ECDYSIS OF INSECTS. 



BY FREDERICK KNAB. 



That air is employed by insects in the process of ecdysis was 

 first brought to my notice while watching a mosquito issue 

 from the pupa. When the mosquito emerges from the pupa 

 it is distended with air far beyond its natural size ; in fact it is 

 inflated to such a degree that the integument is stretched to 

 its utmost. This distension goes so far that the scales of the 

 abdomen, which later overlap to form a complete covering, 

 are separated so that the pale integument is visible between 

 them, while between the segments there is a broad band of 

 naked ?kin which later is folded under the ends of the segments. 

 This inflated condition is gradually acquired during the pupal 

 period. As the pupa grows older it becomes more buoyant, 

 until finally, towards the period of eclosion, it can go down into 

 me water only with great exertion, and when its efforts cease 

 the pupa is immediately carried to the surface. 



A similar inflated condition appears to obtain in Coleoptera. 

 T have noted that in newly emerged beetles the body is much 

 distended. This ts particularly obvious in the thoracic region 

 through the position of the elytra. At this time the elytra are 

 separated from the hind margin of the pronotum by a consid- 

 erable area of smooth integument which disappears beneath 

 the pronotum as the body contracts to its normal dimensions. 



The great tension to which llie insect's covering is subjected 

 at the time of ecdysis by the contained air was demonstrated 

 to me in a striking manner by a chance experience. Last year, 

 while at Cordoba, in Mexico, one of the attendants of the 



