SPIDERS. 353 



•without being able to construct a bridge over water of 

 an inch long. We never observed more than one 

 floating thread produced at the same time ; though 

 other observers mention several. 



The probable commencement, we think, of the 

 floating line, is by the emission of little globules of 

 the glutinous material to the points of the spinnerules 

 — perhaps it may be dropped from them, if not 

 ejected, and the globules being carried off by the 

 current of air, drawn out into a thread. But we give 

 this as only a conjecture, for we could not bring a 

 glass of sufficient power to bear upon the spinnerules 

 at the commencement of the floating line. 



In subsequent experiments we found that it was 

 not indispensable for the spider to rest upon a solid 

 body when producing a line, as she can do so while 

 she is suspended in the air by another line. When 

 the current of air also is strong, she will sometimes 

 commit herself to it by swinging from the end of the 

 line. We have even remarked this when there was 

 scarcely a breath of air.* 



We tried another experiment. We pressed pretty 

 firmly upon the base of the spinnerets, so as not to 

 injure the spider, blowing obliquely over them ; but 

 no floating line appeared. We then touched them 

 with a pencil and drew out several lines an inch or 

 two in length, upon which we blew in order to extend 

 them, but in this also we were unsuccessful, as they 

 did not lengthen more than a quarter of an inch. 

 We next traced out the reservoirs of a garden-spider 

 (Epeira diadema), and immediately taking a drop of 

 the matter from one of them on the point of a fine 

 needle, we directed upon it a strong current of air, 

 and succeeded in blowing out a thick yellow line, as 

 we might have done with gum-water, of about an inch 

 and a half long. 



* Sec Insect Transformations, end of chap. xvi. 



x3 



