ANIMAL LIFE AND THE MICROSCOPE 



The eyes must be examined in every specimen. 

 Most spiders have eight eyes, set like little gems 

 in the front part of the head; some have six eyes, 

 some only two and a few kinds are eyeless, but 

 these last spend all their lives in dark caves, so 

 eyes would be useless to them. When we examine 

 the eyes of wolf spiders we shall observe that they 

 are placed on the tops of little projections so that 

 their owners may better be enabled to see all around 

 them. 



The hairs and scales of many spiders make 

 beautiful objects for the microscope. We must 

 make a point of examining the hairs of the water 

 spider also the scales from the Zebra spider. The 

 latter with their feathery form and iridescent colour- 

 ing, are particularly beautiful. We may advan- 

 tageously spend a moment or two in the examina- 

 tion of the spider's web and the threads of which 

 it is made. The strands radiating from the centre 

 of the web differ from those which are arranged 

 spirally. The latter are covered with a sticky sub- 

 stance as may be seen under the microscope. When 

 these spiral threads are laid down by the spider, 

 the sticky substance covers their whole length in 

 a thin film, but the little architect adds a finishing 

 touch, by pulling the thread as a bowman pulls 

 his bow and then releasing it suddenly. The result 

 of this performance is that the sticky substance 

 forms a series of minute globules over the whole 

 length of the thread. 



In order to be in a position thoroughly to master 

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