THE TRIBE OF THE SOVEREIGNS 193 



teresting points of view that it is a bit diflBcult to know 

 which phases to emphasize. In general, there is a striking 

 similarity in their structure and habits in the earlier stages. 

 The eggs are very nearly alike; the caterpillars resemble 

 one another so closely that even expert entomologists 

 sometimes have to decide what species a collected cater- 

 pillar belongs to by seeing what plant it is feeding upon, 

 and the chrysalids are also very similar. 



Some of the more interesting phases in the development 

 of these insects are discussed in connection with the life- 

 stories of the different species. A phase which is char- 

 acteristic to all of them may well be emphasized here. 

 From the time the caterpillars hatch until they change to 

 chrysalids they illustrate to a marked degree an adaptation 

 through structure and habit which must very largely pro- 

 tect them from attack by birds and other enemies. Their 

 structure and markings are almost grotesque. The body 

 is covered with strange club-like appendages and it is 

 colored with a curious mottling of tones of green, drab, 

 brown, and white which is very difficult to describe but 

 which suggests, as the caterpillar rests upon rough bark, 

 simply a bit of bird dung or some natural excrescence. 

 The caterpillars have the habit of feeding at night and re- 

 maining upon their perches by day, often assuming po- 

 sitions which are very unusual among insect larvae. 

 Such positions, in which they remain motionless for hours 

 at a time, are undoubtedly of protective value and help to 

 conceal the insect. After the caterpillars are half grown 

 they rest not upon the leaves upon which they feed, but 

 rather upon the bark of twigs or branches where their 

 peculiar structure is likely to make them inconspicuous. 



The chrysalids of the Sovereigns are also curiously 



