100 NATURAL ARRANGEMKNT OF INSECTS. 



powers of flight ; and the wings, when the insect is at 

 rest, are never raised perpendicularly. 



(95-) The natural arrangement of this tribe has 

 never been attempted ; nor have the primary groups 

 been yet explained. Dr. Horsfield makes five divisions, 

 according to the variation in the larvae ; but he excludes 

 several aberrant groups, which appear to us to belong 

 strictly to this tribe. We shall, therefore, merely indi- 

 cate what appear to us as primary divisions, leaving the 

 analysis of the whole for further investigation. 



(96.) The Sphingides may be contemplated under 

 three great divisions. The first comprises all those 

 which perform their chrysalis transformation deep in 

 the earth ; the second spin themselves up in a thin web 



