1888.] NATURAL SCIENCES OF PHILADELPHIA. 427 



latioii, he was able to draw out this mass, and was delighted to find 

 that he could restore with very little damage the spider's orb, the 

 central shield and zigzag ribbons being quite intact. 



The cocoons were both of them spun within tents of crossed lines 

 five or six inches long and four or five wide, and had a thickness of 

 between two and three inches. The lines constituting the under 

 edges ot the tents were attached to the post of the stall on which the 

 web was spun. The lower cocoon which was spun first, had the top 

 lines of the surrounding tent stayed against an iron bar used to 

 support meat hooks. The upper tent has its roof lines sustained and 

 drawn out from the post by the foundation line of the orb. The 

 lines of which these tents were spun were of a greenish yellow silk, 

 similar to that which the spider uses in preparing the cocoon. He 

 took the cocoons home and dissected them. The lower one was one 

 and one-fourth inches long, seven-eighths inch wide; was composed 

 of a soft yellow silken plush, and inside was constructed precisely 

 like the ordinary egg-sac of this species. It contained 120 eggs, all 

 ■of tliem sterile. The only peculiarity in the cocoon was that the 

 stem which one usually finds at the top was missing. The second 

 cocoon was not quite so large, one inch long, and five-eighths inch 

 ■wide, but it was more perfect in shape, containing the usual stem. 

 The eggs within this cocoon were also sterile, and the number did 

 not exceed 50. As he had on several occasions counted over a 

 thousand eggs in the cocoon of this species, it will be seen that the 

 spider was not in a normal condition. Indeed he had concieved the 

 idea that in most cases where this spider spins more than one cocoon, 

 it will be found that the eggs are not fertile, and that on the con- 

 trary when the eggs are in the normal condition, but one cocoon 

 will be made. 



We may probably account for the making of the second cocoon 

 by some abnormal condition of the ovaries which prevented the ovi- 

 positing of all the eggs at once. The first lot when extruded were 

 protected in the usual way; subsequently Nature compelled the 

 mother to get rid of the remaining eggs, and, moved by the same 

 impulse that caused her to cover the first lot, she was excited to 

 overspin the second also. 



Tliis species will make an imperfect or but part of a cocoon in 

 confinement, and Dr. McCook exhibited a specimen which shows 

 that she sometimes does likewise in natural site. This is a branch 

 which in one place shows the beginning of a cocoon, being the little 

 cup against which the eggs are always spun, and also what appears 

 to be the inner egg-bag. There is nothing more, and the whole is 

 stayed and shut in by the usual tent-like spinning work. Near by 

 is a perfect cocoon secured in quite the same manner. If we suppose 

 that those two were made by the same spider (as is highly probable) 

 we may infer that the original cocooning purpose of the mother was 

 diverted in some manner, perhaps by alarm, w'hich drove her from 

 the spot. She returned to enclose the work partially done; but 

 moved by the urgency of motherhood, presently found a neighboring 

 site and finished her maternal duty. 



