640 TEXT-BOOK OF ENTOMOLOGY 



that the chrysalis is prevented from falling after the cremaster is withdrawn 

 from the larval skin. It is also principally by this same means that it is enabled 

 to reach the silk with the cremastral hook-pads." 



" Dissected immediately after suspension, the last abdominal segment of the 

 larva is found to be bathed, especially between the legs and around the rectum, 

 in an abundance of translucent, membranous material." 



"An hour or more after suspension the end of the forming chrysalis begins to 

 separate from the larval skin, except at the tip of the cremaster (Fig. 5U7, !>}. 

 Gradually the skin of the legs and of the whole subjoin! (10th segment) 

 stretches, and with the stretching, the cremaster elongates, the rectal piece 

 recedes more and more from the larval rectum, and the sustentor ridges diverge 

 more and more from the cremaster, carrying with them, on the sustainers, a 

 part of the soft membrane." The rectal ligament will sustain at least 10 or 12 

 times the weight of the chrysalis. That of Apatura seems to rely almost 

 entirely on the rectal ligament, assisted by the partial holding of the delicate 

 larval skin. 



FORMATION OF THE PUPA AND IMAGO IN THE HOLO- 

 METABOLOUS INSECTS (THE DIPTEPvA EXCEPTED) 



We have seen that in the incomplete metamorphosis, although 

 there may be as many as five, and possibly seven moults, and in 

 Chloeon. as many as 20, and in Cicada septemdecim perhaps 25 or 30, 

 there is but a slight change of form from one stage to another, and 

 no period of inactivity. And this gradual outer transformation is 

 so far as yet known paralleled by that of the internal organs, the 

 slight successive changes of which do not differ from those observed 

 in the growth of ametabolous insects. With the growth of the 

 internal organs there probably goes on a series of gradual regenera- 

 tive processes, and Korschelt and Heider state that we may venture 

 to assume that each changed cell or group of cells which have be- 

 come exhausted by the exercise of the functions of life are reab- 

 sorbed and become restored through the vital powers of the tissues, 

 so that as the result there goes on a constant, gradual regeneration 

 of the organs. 



While the Hemiptera have only an incomplete metamorphosis, the 

 males of the Coccidae are, as shown by O. Schmidt, remarkable for 

 passing through a complete or holometabolous development, with 

 four stages, three of which are pupal and inactive. Hence, as 

 Schmidt observes, there is here a hypermetamorphosis, like that of 

 the iMcluid;e, Stylopidse, etc. 



Shortly before the end of the larval stage of the male appear the 

 imaginal buds of the eyes, legs, and wings. In the 2d or 1st pupal 



