2GO 



AMKKICAN SPIDERS AND THEIR SPINNINGWORK. 



relative to the sun favorable for such observation, the motion of the 

 air which carried them upward, as well as the rapidity of flight, frustrated 

 many attempts. A position was finally taken beside one of the side posts 

 of the sliding "bars," which being opened gave a point of observation with 

 the back to the sun, the eye upon the object, and a fair opportunity to 

 follow it without the delay of leaping over a high fence, which before had 

 been between the observer and the course of the aeronaut sailing before the 

 wind. Fortune favored patience, and at last a spider took flight in a line 

 which was a little higher than the face. 



Following the aranead at a moderate run, with the eye held closely 

 upon it, I observed that the position of the body was soon reversed ; that 

 is, the head was turned in the direction toward which the wind was blow- 

 ing, instead of the point from which it 

 blew, as before the ascent. Thus the long 

 thread which streamed out above the aero- 

 naut inclined forward, and at the top was 

 in advance of its head. I also observed 

 that the legs were spread out, and that 

 they had been united at the feet by deli- 

 cate filaments of silk. The action by 

 which the spinningwork was accomplished 

 was not noticed, owing to the smallness of 

 the creature, the rapidity of its move- 

 ments, and the difficulty of such an excep- 

 tional mode of observation. But the fact 

 was noted. Tne reason naturally suggested 

 for it is the increased buoyancy resulting 

 FIG. 271. Attitude of ballooning spider just from the increased surface thus offered to 

 nTb:L?ttJr e f 2 - AttitUdeWhen the resistance of the air, provided, of 



course, any reason be required beyond the 



animal's need of some sort of foothold while afloat. Mr. Emerton, 1 in the 

 course of some accurate observations of ballooning spiders, says that the 

 most of them while afloat hung by their spinnerets only, and drew their 

 legs close against their bodies, a posture which I have also sometimes ob- 

 served. 



The spider whose behavior I am now describing was followed for a dis- 

 tance of eighty feet, when it gradually settled downward upon the meadow. 

 Before, or rather during, this ascent a small, white, flossy ball of silk was 

 seen accumulating at the mouth, which, with the peculiar motion of the 

 fore feet, palps, and mandibles, at once suggested the drawing in of a 

 thread. This behavior is not infrequent with spiders under other circum- 

 stances ; indeed, it may nearly always be observed when webs are being 



Flo. 271. 



Fie. 272. 



Spiders," American Naturalist, 1872, pages Ki8-!l. 



