FOOD OF INSECTS. 275 



JuK, Acheta, cockroaches, &c., which are so injurious there to cultivated 

 vegetables. It issues from its hole at night only (never in the day time) 

 to attack these insects ; and so far from having any bird-catching propen- 

 sities, Mr. MacLeay having placed a living humming-bird in the tube of 

 a Mi/gale, it deserted it, leaving the bird untouched.^ It is, however, 

 very possible that other species may attack birds, as is asserted of Mygale 

 Blondii by Palisot deBeauvais, of M. fasciata by Percival in hh Account 

 of Ceylon, and of a species common in Martinique by M. Moreau de 

 Jonnes.- Mygnlc aviculnria, as well as other tropical species, the Euro- 

 pean Cteniza cementaria, and many others, construct in the ground very 

 singular cylindrical cavities, and therein carry and devour their prey. 

 These, being rather the habitations of insects than snares, I shall describe 

 in a subsequent letter. Lycosa saccata, the species whose affection for 

 its young I have before detailed, and not a few others of the same family, 

 common in this country, in like manner seize their prey openly, and when 

 caught carry it to little inartificial cavities under stones. .Dolomedes fim- 

 hriatus^ hunts along the margins of pools ; and Lycosa phatica and its 

 congeners not only chase their prey in the same situation, but, venturing to 

 skate upon the surface of the water itself, 



". . . bathe unwet their oily forms, and dwell 

 With feet repulsive on the dimplinfj well." 



The Rev. R. Sheppard has often noticed, in the fen ditches of Norfolk, 

 a veiy large spider, which actually forms a raft for the purpose of obtain- 

 ing its prey with more facility. Keeping its station upon a ball of weeds 

 about three inches in diameter, probably held together by slight silken 

 cords, it is wafted along the surface of the water upon this floating island, 

 which it quits the moment it sees a drowning insect, — not, as you may 

 conceive, for the sake of applying to it the process of the Humane Society, 

 but of hastening its exit by a more speedy engine of destruction. The 

 booty thus seized it devours at leisure upon its raft, under which it retires 

 when alarmed by any danger. 



The last of the tribe of hunters that it is necessary to particularize are 

 those which, like the tigers amongst the larger animals, seize their victims 

 by leaping upon them. To this division belongs a very pretty small 

 banded species, Salticus scenicus, which in summer may be seen running 

 on every wall. 



To Walckenaer's swimmers, the last of his grand tribes of spiders, 

 including the single genus and species, Argyroneia aquatica, the first line 

 of the above quotation from Dr. Darwin is particularly applicable ; for 

 these actually seize their food by diving under the water, their bodies being 

 kept unwet by a coating of air which constantly surrounds them. — Thus 

 one single race of insects exemplify in miniature almost all the modes of 

 obtaining food which prevail amongst predaceous quadrupeds — the auda- 

 cious attack of the lion, the wily spring of the tiger, the sedentary cunning 

 of the lynx, and the amphibious dexterity of the otter. 



This general view of the stratagems by which the spider tribe obtain 



• Tra/'s. Zuol. Soc. Land. i. 191. " 



^ Shiickard in Ann. of Nat. Hist. viii. 436. 



' According; to M. Walckenaer this spider {Aranea fanbriala L.), A. margivata and A. 

 paludosa De Geer ; as well as Dolomedes limbotus Hahn, and D. marohiatvs of his Faune 

 Fianqaise, are mere varieties of the i>ame species. {Ann. Soc. Ent. de France, ii, 424.) 



