SPOTTED ELEPHANT HAWK-MOTH. 151 



more advanced, they become so conspicuous that 

 their numbers are reduced by marine birds that 

 feed upon them. Sometimes they may be traced 

 by their soil, at other times they may be seen far 

 from the spot where they fed, at the extremity of a 

 tall rush. They are full grown about the middle of 

 September, when they descend into the sand and 

 change into chrysalides, forming a loose case of 

 earth around them, from which they emerge the 

 beginnijig of the following June. Sometimes, how- 

 ever, they remain in the pupa state two seasons, as 

 many other Lepidoptera do ; a wise provision of 

 Nature to prevent any accident from destroying the 

 whole brood. The sand-hills where the larva is 

 found are of great extent and magnitude, and must 

 have been collected by the winds and storms to 

 which they are constantly exposed during the 

 winter the whole soil is frequently removed, so as 

 completely to alter the surface of the country; a 

 great number of the pupa must consequently be 

 destroyed or buried at a great depth below the 

 surface, where probably they lie hid until they are 

 brought to light and life by the influence of the 

 elements*." 



* Curtis' British Ent. i. p 3. 



