190 



INTRODUCTION TO ZOOLOGY 



CHAP. 



Hibernation. 





o^thellilk 



whilst the new skin hardens. When limbs have been lost, 

 they are renewed at the next moult, though they are at first 

 relatively small. 



Spiders, young and old, all disappear before 

 winter, but though many perish, many survive 

 after hibernating through the cold months. Under favour- 

 able conditions, they may live for two 

 or three years. 



It was thought at one 

 time that it might be pos- 

 sible to utilise the silk 

 spun by spiders, in the same way as 

 that of silkworms, and certain experi- 

 ments have been made with the silk 

 from the cocoons of the common cross 

 spider, the cocoon silk being much 

 stronger than that used in constructing 

 the web. It was found, however, that 

 though it was possible to use the silk 

 indeed certain stockings and mittens 

 were actually woven of it it was 

 inferior in strength and quality to that 

 of the silkworm. 

 Also the spiders are 



FIG. 120. A Spider moult- exceedingly difficult 

 ing: a, the empty skin ; . , under ron 



b, the spider. (After t0 Kee P ] 

 Grant Allen.) trol. 



When the young 



spiders first disperse in the 

 Gossamer. . , 



autumn or spring, they do so in 



a curious way. They climb to some ex- 

 posed point, and there each lifts its 

 body as high as it can, standing on 

 the tips of its feet. In this position it 

 begins to exude silk from its spinnerets. FIG. 121. A young 

 The little mass of silk is soon caught on Spider preparing to 

 some slight current of air, and is drawn flfter Emerton. f 

 out until quite a long thread is floating 

 in the air. When the wind catches this with sufficient 

 force, the spider seizes the thread with its claws and is 

 wafted away, borne by the silk streamer. In this way 



