1903.] NATURAL SCIENCES OF rHlLADELPHIA. 89 



The number of cocoons, and the dates of their making, were as 

 follows : 



(1) 9 No. 33: June 10 (did not hatch as it had not been cut). 



(2) 9 No. 54: May 19, hatched June 7; a second cocoon hatched 

 July 9. 



(3) $ No. 57: May 12, hatched June 2; July 2, hatched July 19. 



(4) 9 No. 61: May 9, an abnormal cocoon. 



(5) ? No. 63: June 7, she cut it open but the young never hatched, 

 for she had probably opened it too soon ; July 25, an irregularly shaped 

 cocoon, which she destroyed by chewing on the same day. 



(6) 9 No. 65: May 9, hatched Jmie 1; June 10 or 11, hatched 

 July 1. 



(7) 9 No. 58: May 18, hatched June 7; July 12, a verj^ small cocoon 

 which she ate. 



(8) 9 No. 177: June 4, eaten by the mother; June 29, eaten by the 

 mother. 



Thus none of my captives made more than two cocoons. 



Care of the Young. — The cocoons are carried suspended from the 

 spinnerets, and generally kept well elevated above the ground, the 

 spinnerets being firmly fastened to one of the rounded sides. The 

 mother bites open the cocoon to allow the escape of the young, and 

 unless it is so opened the young cannot get out of it. This biting of 

 the cocoon was observed in several individuals; sometimes it lasts 

 through several days, for only a short time each day; in one case 

 the mother started to cut the cocoon a full week before the young 

 emerged; the following is a typical case: 9 No. 65 on May 30 was first 

 observed cutting her cocoon. On May 31, at 9.10 P.M., she was cutting 

 it again. The cocoon was held beneath her cephalothorax by the 

 first and third pairs of legs and by the abdomen deflected down- 

 ward, in such a position that the plane of its largest circumference 

 (its equator) coincided with her median plane. With her chelicera 

 she slowly tore away the thick outer covering along the line of the 

 equator, her palpi aiding, and at the same time her legs slowly rotated 

 the cocoon. This cutting is not a continuous process, but interrupted 

 by frequent short rests as if she were noticing movements of the young. 

 At 10.22 she suspended the cocoon from her spinnerets, and cut 

 again from 10.35 to 10.39. The cut was now very deep, so that 

 through it the spiderlings could be seen moving within the cocoon. 

 Next morning several of the young had crawled out upon her body, and 

 at midday she finally dropped the cocoon, although there were still 

 young within it. Some mothers open their cocoons with a cut extend- 



