SPIDERS. 



153 



from wantonness but from necessity. It must kill, or it must 

 cease to live. 



Gossamer, the origin of which was formerly conjectural, is 

 now known to be the production of a minute Spider. Spencer 

 speaks of it as " scorched dew," and Thomson regards it as 

 " the filmy threads of dew evaporate." 



Spiders have been divided into families, which present very 

 considerable differences in their modes of life. Some are 

 hunters, and live by the chase ; some leap upon their prey ; 

 some more deliberately move sideways or backwards, as the 

 exigency requires; some fix long threads and prowl about 

 them to secure their game, while others construct nets of 

 various kinds in the air, or exercise their skill in the water. 



Not less varied arc their habitations. Perhaps the most 

 remarkable is that of the My gale ccementaria, who, having 

 formed a subterraneous tube or gallery, lines it with silk, and 

 constructs a door formed of several coats of cemented earth 

 and silk. "This door (Fig. 146) the ingenious artist fixes 

 to the entrance of her gallery by a hinge of silk; and, as if 

 acquainted with the laws of gravity, she invariably fixes the 

 hinge at the highest side of the oprn"'^, so that the door, 

 when pushed up, shuts again 

 by its own weight." The 

 part against which it closes 

 with great accuracy, and the 

 defences by which it is secured, 

 are not less excellent as me- 

 chanical contrivances. 



The female Spider is remark- 

 able for her parental affection. 

 One species (Epeira fasdatd) 

 makes an elaborate envelope for 

 her eggs, attaches it to a branch 

 of a high tree, and guards it 

 with ceaseless vigilance. The habits of another are thus 

 described by Professor Hentz : " When a mother is found with 

 the cocoon containing the progeny, if this be forcibly torn 

 from her, she turns round and grasps it with her mandibula3 

 (mandibles). All her limbs, one by one, may then be torn 

 from her body without forcing her to abandon her hold. But 

 if, without mangling the mother, the cocoon be skilfully 

 removed from her, and suddenly thrown out of sight, she 



Fig. 14G. NKST OF MVGALK. 



