AS BUG ABBS SPIDEBS. 



6 79 



to serve a most remarkable physiological end in connection with gen- 

 eration. The palpi of the male are furnished with several hooks, and a 

 kind of cup (Fig. 8), while those of the female taper to a point, and 

 are armed at the extremity with a toothed comb, like those at the end 

 of the feet, and with several long, sword-shaped hairs. 



But if, at the anterior extremity of the spider, we see in miniature 

 the most perfect enginery of destruction, at its posterior extremity 

 there is an equally marvellous device for the work of construction. 

 If you direct your lens to the abdominal segment, you will observe 

 what is represented in Fig. 10. The projections there seen are called 

 spinnerets, and are contrivances for producing the web. One pair is 

 prominent, the remaining two pairs having the appearance of circlets 

 (Fig. 10, ), and they are all studded over with rows of little micro- 

 scopic tubes (Fig. 10, b b). From these minute tubes there exudes a 

 glutinous substance prepared in the spider's body, which solidifies into 



Fig. 10. 



-3* 



: ..... , - I 



a. 



* ~ w 



Posterior Portion of Spider's Body, showing the Sis Spinnerets. a. Shorter Spinnerets, with Circlets 

 of Tubes ; a*, the same magnified ; bob, Spinning-tubes on Long Spinnerets ; b*, Single Tube 

 magnified. 



a fine, strong filament as soon as it is exposed to the air. The micro- 

 scope lias proved that every one of these almost invisible fibres is 

 composed of hundreds of finer ones, just as a ship's cable is formed of 

 minute hempen fibres, while the main strand is spun far more rapidly 

 than the eye can follow the process. The strength thus secured is 

 very great, and the line is not only strong but elastic, like an India- 

 rubber thread. Leuwenhoek, the renowned microscopist, who studied 

 this subject carefully, made some extraordinary statements in regard 

 to the minuteness of these threads. Some spiders, he says, that are 

 not larger than a grain of sand, spin complex cords of which it would 

 take millions to equal in thickness one of the hairs of his beard. If 

 we ask why the mechanism was not simplified so that the animal 

 should pay out only a single line, the obvious reply is that the multi- 

 tude of finer filaments were necessary for quick drying and the firmest 



