1 10 The Colours of Animals. 



hawk-moths. In one, the Death's Head, the violet 

 colour of the side stripes certainly renders the insect 

 less conspicuous among the flowers of the potato, 

 on which it feeds. In the Oleander Hawk-moth 

 there are two blue patches, which, both in colour 

 and form, curiously resemble the petals of the 

 periwinkle, on which it feeds. In the third species, 

 the small Elephant Hawk-moth, the bluish spots 

 form the centres of the above-mentioned eye-like 

 spots. 



ii. In one family,* as already mentioned, the 

 caterpillars are very often brown, and closely re- 

 semble bits of stick, the similarity being much in- 

 creased by the peculiar attitudes they assume. On 

 the other hand, the large brown caterpillars of certain 

 Hawk-moths are night feeders, concealing them- 

 selves on the ground by day ; and it is remarkable 

 that while those species, such as the Convolvulus 

 Hawk-moth, which feed on low plants, turn brown 

 as they increase in age and size, others, which 

 frequent trees, and cannot therefore descend to 

 the ground for concealment, remain green through- 

 out life. Omitting these, there are among the 

 larger species, 17 which are brown, of which 12 

 are hairy, and two have extensile caudalf filaments. 

 The others closely resemble bits of stick, and place 

 themselves in peculiar and stiff attitudes. 



* The Geometridct. 



t Extensile capable of being extended; Caitdal=* belonging to 

 the tail. 



