INSECTS 



species of insects, and with some they involve a consider- 

 able degree of actual growth and change in the form of 

 certain parts. The true transformation process, then, is 

 really a period of rapid reconstructive growth preceding 

 and following the molt, in which the shedding of the skin 

 is a mere incident like the raising of the curtain for a new 

 act in a play. During the intermission the actors have 

 changed their costumes, the old scenery has been re- 

 moved, and the new has been set in place. Thus it is 



Th Ab 



Md 



Fig. 136. Externa! structure of a caterpillar 



Ab, abdomen; AbL, abdominal legs; //, head; L\ y Lz, Z.3, the thoracic legs; Md, 



.jaws; Sp, breathing apertures; Tb, thoracic segments 



with the insect at the time of its transformation — the 

 special accouterments of the young have been removed, 

 and those ot the adult have been put on. 



The life of the insect, however, would not make a good 

 theatrical production; it is too much of the nature of two 

 plays given by the same set of actors. The young insect 

 is dressed for a performance of its own in a stage setting 

 appropriate to its act; the adult gives another play and is 

 costumed accordingly. The actor is the same in each 

 case only in the continuity of his individuality. His 

 rehabilitation between the two acts will differ in degree 

 according to the disparity between the parts he plays, 

 that is, according to how far each impersonation is re- 

 moved from his natural self. 



It is evident, therefore, that the transformation changes 

 of an insect will differ in degree, or quantity, according to 



f 242] 



