INVESTIGATION OF THE PUSS MOTH 309 



been traced in the case of the Puss Moth has gone on in 

 every branch of natural history, new contrivances being 

 perpetually discovered and old ones better described. 

 Two or three centuries of such labour have made us so 

 rich in natural knowledge that we grieve at times to 

 think how small is the fraction which the best memory 

 can retain. 



