2'4« Mr. J, Jenner Weir on 



onoilgh to obtxin about one hundrecl young larvse a few 

 •liours old, having* indeed only just emerged from the 

 egg, I introduced them into the avairy on their natal 

 leaf. The movement of the little creatures soon attracted 

 the notice of a Siskin ; the bird tasted one of the minute 

 caterpillars, shook its beak as if it were disagreeable, 

 and left the rest undisturbed ; a Redpoll followed, bnt 

 . the result was the same. A West- African insectivorous 

 Finch, Textor erythrorhynchus, next tried their flavour, 

 but soon left them, evidently not liking it. No further 

 molestation took place, and the minute larvas remained 

 undisturbed. 



I cannot think that, in this case, the rejection arose 

 from the hairiness of the larvse. I imagine that it was 

 caused by their disagreeable flavour, and that the birds 

 were deceived into tasting them, because the character- 

 istic warning hairs were undeveloped ; and that, on the 

 other hand, when the caterpillars are more developed, 

 the hairs serve as a caution to the birds, that the larvae 

 so clothed are uneatable. 



The results obtained with spined larvse were very 

 similar, and the deductions I make are the same. The 

 larvEe experimented on were those of Vanessa urtica^, and 

 Vanessa lo; these species both, as is well known, feed 

 on the tops of JJvtica clioica, without any attempt at con- 

 cealment ; the larvse wore utterly disregarded by all the 

 birds, and were allowed to crawl about the aviary for 

 days. The metallic looking chrysalides of the two species 

 were also invariably rejected, thus showing that the 

 .spines were not the cause of the uneatableness of the 

 larvse. 



Larvse 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 branches covered with the web of Hyponomeuta 

 cvonymclla were introduced into the aviary, those larvse 

 only which ventured beyond the protection of the web 

 •were eaten. 



The experiments I was anxious to try were those with 

 smooth-skinned, gaily-coloured caterpillars, which never 

 conceal themselves, but, on the contrary, appear to court 

 observation. 



