xiv] THE ENEMIES OF SPIDERS 123 



are terrible enemies at hand from which it has little 

 or no protection. Birds, of course, come first, for 

 to most insectivorous birds spiders are acceptable 

 morsels. I have seen a hedge sparrow going con- 

 scientiously over a trellis work and picking out all 

 the spiders from the nooks and corners. Then in- 

 sectivorous mammals make no distinction between 

 the Insecta and the Arachnida, and often eat spiders 

 with avidity, as also will toads and lizards. 



Moreover, Ichneumon flies do not confine their 

 attention to cocoons, but often attack well-grown 

 spiders. They invariably lay their eggs on one spot- 

 at the very front of the abdomen, near the cephalo- 

 thorax, where the spider is powerless to dislodge 

 them. The egg hatches out to a grub which is a 

 veritable " old man of the sea " on the spider's back, 

 and there it remains until it causes the death of its 

 victim by feeding on the contents of the abdomen. 

 Four such Ichneumon flies have been found to attack 

 the gar den -spider, and no kind of spider seems 

 exempt. How they contrive to deposit their eggs in 

 the proper place without great danger of themselves 

 falling a prey to their victims is a mystery. To 

 venture into a garden-spider's web for the purpose 

 would seem a fool-hardy proceeding. The actual 

 deposition of the egg has seldom been witnessed, but 

 in one of the few cases that have come under 

 observation the spider made little resistance and 



