Packard.] RELATIONS or INSECTS TO MAN. 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. Larvae 
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 
theyreb are left unmolested. When certain branches cov¬ 
ered with the web of Hyponomeuta evonymella (a little moth 
of the Tinea family) were introduced into the aviary, those 
larvae only which ventured beyond the protection of the web 
were eaten.” 
“ Smooth-skinned, gayly-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” were 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 larvae 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 may 
refer to those which are indirectly so. Professor Leidy 
has, as we find in the “American Naturalist” (vol. vi, p. 
694), 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 diffluent 
matter of some fungi of the Phallus impudicus. He caught 
25 
