Iniecis and Insectivorotis- Birds, 25 



My first experiment was with the larvae of Ahraxas 

 grossuJariata ; and in order that the birds might be fairly- 

 attracted towards them, I placed them on a shelf in the 

 aviary amongst other eatable species. I watched the 

 birds carefully ; they soon ate up all the well-relished 

 and dull-coloured species, but left Ahraavs grossulariata 

 untouched. I quitted the aviary for some hours, but on 

 my return, they were still crawling about unmolested. 



The same result followed the experiments with Diloha 

 cceruleocephala, and Anthrocera filvjpendulce, both con- 

 spicuous species in the lai^val state. 



I was most desirous to try the larvae of the genus 

 Cucullia, and at last succeeded in getting several of 

 C'ucidlia vtrhasci of different sizes. These larvae, as is 

 well known, feed on the leaves of Verhascwn thapsus, and 

 are most beautifully coloured With bright blue, yellow, 

 and black ; and their skins are perfectly smooth. It 

 appeared to me that experiments with this species 

 would be conclusive ; and I confess to feeling very ex- 

 cited when I made them. I had however the pleasure of 

 finding that this crucial test did not fail. The larvce 

 were placed on the feeding shelf one afternoon. I found 

 them there after dinner, and the next day some were 

 still living, and quite-rmnrole&ted. 



I will now add a few words on those larvse which are 

 eaten greedily by birds, and my remarks on the subject 

 will be brief; it will be unnecessary to detail all the 

 experiments made, as the results are easily generalized. 



All caterpillars whose habits are nocturnal, dull- 

 coloured, with fleshy bodies and smooth skins, are eaten 

 with the greatest avidity. 



Every species of green caterpillar is also much 

 relished. 



All Geometrce, whose larvas resemble twigs as they 

 stand out from the plant on their anal prologs, are in- 

 variably eaten. 



To sum up, I have quite satisfied myself that insecti- 

 vorous birds, as a general rule, the Cuckoo, perhaps, 

 being an exception, refuse to eat hairy larvae, spinous 

 larvEe, and all those whose colours are very gay, and 

 which rarely, or only accidentally, conceal themselves. 



On the other hand, they eat with great relish, all 

 smooth-skinned larvEe of a green or dull-brown colour, 

 which are nearly always nocturnal in their habits, or 



