MICROSCOPIC OBJECTS. 85 



Fig. 169. Foot of the Garden-Spider (Epeira diadema), 



x60. 



The leg of a Spider, as will be seen on referring to the 

 drawing, is admirably adapted for its work; the last joint of the 

 tarsus being generally furnished with three saw-like claws, by 

 means of which the Spider is enabled to retain its hold upon 

 the web and to pass down any part of the same with great 

 rapidity. 



The leg simply requires to be well washed with a camel's- 

 hair brush, dried under pressure, soaked in turpentine, and 

 mounted in balsam. 



Fig. 170. Spinnerets of the Garden-Spider (Epeira 

 diadema) , x 20. 



At the base of the abdomen are situated three pairs of 

 conical-shaped bodies, these are the spinnerets ; and on re- 

 ferring to the drawing a number of minute tubes will be seen 

 on the summit of each. From these tubes the viscid matter 

 is drawn in single filaments, and it collects into one extremely 

 fine thread, with which the Spider manufactures it web. The 

 number of these spinning-tubes varies from about 1000 to 

 100 according to the age of the insect &c. The bases of the 

 spinnerets are closely covered with hairs to protect the tubes 

 from injury. The glands which secrete the viscid matter of 

 which the web is composed occupy the interstices of the other 

 viscera of the abdomen. 



The part containing the spinnerets simply requires to be 

 placed in liquid potassa for two or three hours, well washed, 

 dried under pressure, and mounted in balsam. 



