THE PUPA. 31 



black and red. But some are quite delicately tinted and 

 marked, or shine as if gilded with burnished gold. It 

 was from this gilded appearance that the terms Chrysalis 

 and Aurelia were applied to the whole, since the alche- 

 mists mistook this for real gold. Some others have the 

 lustre of real silver and are beautifully marked and spot- 

 ted. 



They are nearly all of a little different color when they 

 first assume the pupa from what they soon after assume. 



The duration of an insect's existence in the pupa state 

 varies from two or three days to as many weeks, months 

 or even years. 



As a general rule the small pupee continue their state 

 a shorter time than the large pupae. 



The temperature they are exposed to also has much in- 

 fluence, as those exposed to an uniform and higher degree 

 of heat more rapidly pass into the perfect states and it 

 can also be greatly retarded by being placed in a low 

 temperature. 



But some pupse have a periodic time for passing into 

 the perfect state, quite independent of the circumstances 

 of temperature. Such, for example, are the Ephemerae, 

 which, in the proper season of the year, mature at be- 

 tween eight and ten in the evening, regardless of cold or 

 rain, and certain species of silk worm and hawkmoths, 

 which break forth from the pupa at sunrise. 



The sex of the pupae may be distinguished chiefly by 

 the male being smaller than the female, and often by the 

 evident organs of oviposition of the female doubled up on 

 the abdomen, as the tongue sometimes is on the thorax. 



Incomplete pupae often continue their powers of motion 



