Packaud ] r.ELATIOXS OF I^TSECTS TO M.i^T. 89 



was disposed to consider that the " flavor of all these cater- 

 pillars is nauseous, and not that the mechanical trouble- 

 someness of the hairs prevents their being eaten. Larvte 

 which spin webs and are gregarious are eaten by birds, but 

 not with avidity' ; they appear very much to dislike the web 

 sticking to their beaks, and those completely concealed in 

 the web are left unmolested. When certain branches cov- 

 ered with the web of Iluponomeuta evonymella (a little moth 

 of the Tinea family) were introduced into the aviary, those 

 larvaj only which ventured bej^ond the protection of the web 

 were eaten." 



"Smooth-skinned, gaylj'-colored caterpillars (such as the 

 currant Abraxas or span worm. Fig. 39), which never con- 

 ceal themselves, but on the contrary appear to court obser- 

 vation" Avere not touched by the birds. He states, on the 

 other hand, that "all caterpillars whose habits are nocturnal 

 and are dull-colored, with fleshy bodies and smooth skins, 

 are eaten with the greatest avidity. Every species of green 

 caterpillar is also much relished. All Geometrae, whose larvae 

 resemble twigs, as they stand out from the plant on their 

 anal prolegs, are invariably eaten." Mr. A. G. Butler of 

 London has also found that frogs and spiders will not eat the 

 same larvse rejected by birds, the frogs having an especial 

 aversion to the currant span worms {Abraxas and Halia)." 



Before leaving the subject of poisonous insects we maj^ 

 refer to those which are indirectly so. Professor Leidy 

 has, as we find in the "American Naturalist" (vol. vi, p. 

 C94), entertained the opinion that flies are probably a 

 means of communicating contagious disease to a greater 

 degree than was generally suspected. "From what he ob- 

 served in one of the large military hospitals, in which hos- 

 pital gangrene had existed during the late rebellion, he 

 thought flies should be carefully excluded from wounds. 

 Recently he noticed some flies greedily sipping the diflhient 

 matter of some fungi of the Phallus impudicus. He caught 



25 



