INTRODUCTION. XXXVll 



Chesias spartiata of Stephens,) a species which I 

 had not observed before, and which has disappeared 

 again since the removal of the broom on which the 

 larva feeds. The Caterpillar of Acherontia Atropos, 

 (Death's-head Sphinx,) it is well known, feeds on 

 the potato, the very extensive cultivation of which 

 vegetable root in the present day, will at once 

 account for the far more frequent occurrence of 

 this fine insect of late years than formerly. We 

 are informed, by an able practical entomologist, 

 that some of the fir-feeding Lepidoptera, (the French 

 Sphinx pinastri and Geometra piniaria,) which 

 formerly occurred in scarcely any other part of this 

 island, save Scotland or the north of England, have 

 of late years, since the growth of firs has been more 

 extensively encouraged, been taken, one or both of 

 them, in great abundance in the more northern parts.* 

 The same law, or something analogous to it, holds 

 good also in the vegetable world. Plants sometimes 

 spring up, as it were spontaneously, or at least 

 nobody knows how, as soon as the soil and situation 

 are rendered suitable to their growth." 



The field of Nature is of vast and ever boundlesa 

 extent, and the objects which lie within it are exceed- 

 ingly numerous and diversified. To the mind, 



* See HA WORTH'S Lepidoptera Brit. p. 278, 279. 



