66 ON PLANTS AND INSECTS. [lect. 



subterranean feeders, and are devoid of any striking 

 colour. This leaves 122 species, out of which sixty- 

 eight are hairy or downy ; and of these, forty-eight are 

 marked with black or grey, fifteen brown, or brownish, 

 two yellowish-green, one "bluish-grey, one striped with 

 yellow and black, and one reddish-grey. Of the two 

 yellowish-green hairy species, which might be regarded 

 as exceptions, Z. lonicerce is marked with black and 

 yellow, and N. albulalis is variable in colour, some 

 specimens of this caterpillar being orange. This last 

 species is also marked with black, so that neither of 

 these species can be considered of the green colour 

 which serves as a protection. Thus, among the moths 

 tabulated, there is not a single hairy species of the usual 

 green colour. On the other hand, there are fifty species 

 with black or blackish caterpillars, and of these, forty- 

 eight are hairy or downy. 



In ten of our larger moths the caterpillars are more 

 or less marked with red. Of these, three are hairy, one 

 is an internal feeder, four have reddish lines, which 

 probably serve for protection by simulating lines of 

 shadow, and one {D. euphorbia) is inedible. The last, 

 D. livornica, is rare, and I have never seen the cater- 

 pillar ; but, to judge from figures, the reddish line and 

 spots would render it, not more, but less conspicuous 

 amongst the low herbage which it frequents. 



Seven species only of our larger moths have any blue ; 

 of these four are hairy, the other three are hawk-moths. 

 In one {A. atropos) the violet colour of the side stripes 

 certainly renders the insect less conspicuous among the 

 flowers of the potato, on which it feeds. In C. nerii 

 there are two blue patches, which, both in colour and 



