1884.] NATURAL SCIENCES OF PHILADELPHIA. 139 



experience. Returning to his desk in an hour and a half, he was 

 once more assured by the sight of a round silken ball dangling 

 from the apex of the spider's abdomen, held fast by short threads 

 to the spinnerets. The cushion, however, had disappeared. 



The mystery (as it had seemed to him) was solved : the Lycosa 

 after having placed her eggs in the centre of the silken cushion, 

 and covered them over, had gathered up the edges and so united 

 them and rolled them as to make the normal globular cocoon of 

 her genus, which she at once tucked under her abdomen in the 

 usual way. This v/as a most interesting observation, and Dr. 

 McCook thought had not before been made ; at least Lycosa's 

 manner of fabricating a cocoon had been heretofore unknown to 

 him ; and by reason of her subterranean habit the opportunity to 

 observe it was rare. He had often wondered how the round egg- 

 ball was put together, and the mechanical ingenuity and simplicity 

 of the method were now apparent. The period consumed in the 

 whole act of cocooning was less than four hours ; the act of ovi- 

 positing took less than half an hour. Shortly after the egg-sac 

 was finished, the mother cut her way out of the silken cover. She 

 had evidently thus secluded herself for the purpose of spinning 

 her cocoon. While feeding the spider some flies, the cave was 

 accidentally filled up, and no effort had been made to dig another, 

 although it is the custom of this genus, in natural environment, 

 to remain pretty closely within such a habitation while carrying 

 the cocoon. 



One month after the above date (June 4), the spider was 

 found with the young hatched, and massed upon her body from 

 the caput to the apex of the abdomen. The empty egg-sac still 

 clung to the spinnerets, and the younglings were grouped over 

 the upper part of the same. The abdomens of the little spiders 

 were of a light yellow color, the legs a greenish brown or slate- 

 color, and the whole brood were tightly compacted upon and 

 around each other, the lower layers apparently holding on to the 

 mother's body, and the upper upon those beneath. Twenty-four 

 hours thereafter, the cocoon-case was dropped, and the spiderlings 

 clung to the mother alone. An examination of the cocoon showed 

 that the young had escaped through the thin seam or joint 

 formed by the union of the egg-cover with the circular cushion, 

 when the latter was pulled up at the circumference into globular 

 shape. There was no flossy wadding within — as is common with 

 orb-weaving spiders, for example — nothing but the pinkish shells 

 of the escaped young. On June 11, about one hundred of the 

 spiderlings had abandoned the maternal perch, and were dispersed 

 over the inner surface of the jar, and upon a series of lines 

 stretching from side to side. About half as many more remained 

 upon the mother's back; but by the 13th, all had dismounted. 

 Meantime, they had increased in size at least one-half, apparently 

 without food. 



