426 PROCEEDINGS OF THE ACADEMY OF [1888. 



because of their unnatural condition. The spiderlings were not 

 counted but they were very numerous. 



Througli information kindly given by Dr. Leidy, the President of 

 the Academy, Dr. McCook was permitted to study on the olst 

 •October last, (1888,) an example of this duplex cocoonery which 

 occurred in the Farmer's Market of Philadelphia. He visited the 

 market house at 12th and Market Streets, which is one of the largest 

 and best of its sort in our city. He had no difficulty in finding the 

 ■cocoons which had been preserved, and made a study of them which 

 is here submitted. The facts are as follows : Some time during the 

 .-summer of the present year, Mr. Charles Moore observed upon his 

 meat stall a spider whose beauty attracted his attention, and which 

 proved to he a female of Argiope cophiiiaria. She had probably 

 been brought into the market from the country, hidden among the 

 leaves of some vegetable, as the huge Tarantula and the large Lateri- 

 grade spider, Ileterapoda vemitoria, are brought to our port from the 

 West Indies in bunches of banannas and other fruits. However, 

 :she may have floated in as a young balloonist from some city garden, 

 for the species is very abundant in open grounds within city limits. 

 Instead of brushing her down and killing her after the usual manner 

 of dealing with such creatures, Mr. jMoore took a fancy to preserve 

 lier, and would allow no one around his stall to inflict any injury 

 upon her. Her movements were necessarily somewhat impeded and 

 modified by the business of the place, and several times she changed 

 her web until at last she spun it in a position that was practically 

 free from interruption. This was quite at the top of the stall, the 

 main foundation line, two feet long, was stretched from a standard 

 beam to the end of a projecting iron hook-rod. The spider became 

 quite a favorite and those around the stall amused themselves by 

 feeding her with flies. She would take the flies thrown into her web, 

 -coming down from her habitual perch against the central white 

 :shield which characterizes her snare, to get them. 



Sometime between the 10th and 20th of August she began to make 

 her first cocoon. jNIr. INIoore, of course, made no careful study of the 

 process; but he said that it was spun early in the morning; that at 

 ^irst the spinning work thrown out was as white as snow; that the 

 •spider then began to wrap it up, and it grew smaller and smaller as 

 .she wrapped, rolling it around with her feet. After the white ma- 

 terial had been s{)un, a brownish silk was used, and when the spider 

 had completed her task, the ball was not more than half as big as 

 it seemed to him at first. About a week or ten days thereafter, she 

 made a second cocoon, placing it in a position 15 inches above the 

 other. Both of the cocoons were in site precisely as left by the 

 .spider. The web, however, had been destroyed, but the speaker 

 noticed that an irregular mass of spinning work was laid along the 

 beam between the two cocoons, which after a little observation 

 proved to be the last snare which the spider had made in a collapsed 

 •condition. The foundation line had been broken and the web had 

 thus shrunken up against the post. By delicate and careful mauipu- 



