242 Sir Jolui Lubbock on 



which frequent trees, and cannot therefore descend to the 

 ground for concealment, remain green throughout hfe. 

 Omitting these, we find in the table 23 brown species, of 

 which 12 are hairy, and two have extensile caudal filaments. 

 Three at least of the others, though not GeometridcB, 

 closely resemble bits of stick, and place themselves in 

 peculiar stiff attitudes. The others are small species. 



It has been suggested to me by Mr. Meldola that in 

 certain instances haii's may sei've as a protection, instead 

 of acting simply as signals of distastefuluess. This appears 

 to be the case with such species as PcBcilocampa Pojndi, 

 Avhich has a fi-inge of long hairs along the sides, just 

 above the legs. In these cases the insects rest by day on 

 lichen or bark, to which they assimilate in colour and 

 marking, and in such situations would stand a chance of 

 detection, in spite of their protective colouring, if they 

 stood out in bold relief, and cast a sharp shadow. The 

 hairs may thus have been acquired for the purpose of 

 shading off the sharp outline of the caterpillars, an analo- 

 gous function being probably fulfilled by the row of fleshy 

 protuberances along the sides of Lasiocampa quercifolia, 

 and species of Catocalci. 



Thus, summing up the caterpillars, both of the butter- 

 flies and moths, out of the 88 spiny and hairy species 

 tabulated, only one is green (Z. Sybilla?), and even this 

 may not be protectively coloured, since it has yellow warts 

 and white lateral lines. On the other hand, a very great 

 majority of the black and brown caterpillars, as well as 

 those more or less marked with blue and red, are either 

 hairy or spiny, or have some special protection. The 

 general review, then, which I have here very imperfectly 

 attempted, confirms, in a remarkable manner, the views of 

 the eminent naturalists to whom I have referred. 



Note. — In the following tables the general ground 

 colour of the dorsal surface of the full-grown caterpillar 

 is indicated in the respective columns by an asterisk. 

 Special markings and their colours are described in the 

 column headed " Kemarks." Larv^ merely pubescent 

 are not considered hairy. 



