248 EVENINGS AT THE MICROSCOPE 



stud the spiral circles of one of these nets. Mr. Black- 

 wall, the able and learned historian of the tribe, has esti- 

 mated that as many as 87,360 such pearly drops occurred 

 in a net of average dimensions, and 120,000 in a large net 

 of fourteen or sixteen inches diameter; and yet a Spider 

 will construct such a net, if uninterruped, in less than 

 three-quarters of an hour. 



Scarcely less admirable is the ease and precision with 

 which the little architect traverses her perpendicular or 

 diagonal web of rope; a skill which leaves that of the 

 mariner who leaps from shroud to backstay in a ship's 

 rigging immeasurably behind. To understand it, however, 

 in some measure, look at this last joint of one of the feet 

 of our well- used Clubiona. It is a cylindrical rod, ending 

 in a rounded point; every part of its surface is studded 

 with stiff, rather long, horny bristles, which, springing 

 from the side, arch inward toward the point. Now this 

 array of spines effectually prevents a false step, for if any 

 part of . the leg, which is sufficiently long, only strikes the 

 thread, the latter is certain to slip in between the bristles, 

 and thus to catch the leg. But more precision than this 

 is requisite; especially when we observe with what deli- 

 cacy of touch the hinder feet are often used to guide the 

 thread as it issues from the spinnerets, and particularly 

 with what lightning-like rapidity the larger net- weavers 

 will, with the assistance of these feet, roll a dense web of 

 silk around the body of a helpless fly, swathing it up, like 

 an Egyptian mummy, in many folds of cloth, in an instant. 



Look, then, at the extreme tip of the ultimate joint. 

 Two stout hooked claws of dark horny texture are seen 

 proceeding from it side by side, and a third of smaller size, 

 and more delicate in appearance, is placed between them, 



