128 ARTICULATES: INSECTS. 



state it is called a pupa, a word meaning infant, 

 from a slight resemblance that some insects in this state 

 bear to an infant clothed with bandages, according to a 

 custom among the Romans ; and it is also often called 

 a chrysalis, from a Greek word which means gold, be- 

 cause some of the pupa3 are adorned with golden spots ; 

 in the third state it is called a perfect insect, or imago, 

 from a word which means image, because the image 

 concealed in the skin of the pupa has come forth. 

 These different states are plainly shown on page 127. 

 Some caterpillars spin a silken covering, which is 

 called a cocoon, from a word which 

 means a shell ; all the silk of the 

 world comes from the cocoons of 

 these little creatures. Insects 

 which pass through the changes 



Fig. 253. -Cocoon. ^ degcribed are gaid to unde rgO 



a complete transformation ; but there are some insects 

 which do not change their form so completely. Grass- 

 hoppers, for instance, are active during their whole 

 lives, never passing through an inactive pupa state. 

 When hatched from the egg they have legs, but no 

 wings ; later their wings begin to grow, and at length, 

 having shed their skin several times, each time appear- 

 ing with longer legs and more perfect wings, they reach 

 their full growth, shed the skin for the last time, and 

 appear as perfect, or adult grasshoppers. Such insects 

 undergo only a partial transformation. 



Insects are the most numerous of all the classes of 

 animals, there being several hundred thousand kinds. 

 And the study of Insects is one of the most interest- 

 ing and fascinating in which one can engage. The 

 study of Insects is also very important, that we may 



