340 Fiftieth REroRT ox the State Museum 



spinner leaving it, and commencing to cover the leaf-stalk with a firm 

 envelope of silk, which, when completed, will be stronger than you car> 

 break without forcible pulling. You will now be given a favorable oppor- 

 tunity as the caterpillar's head sways from side to side, to note 

 the two silken semi-fluid threads emitted from the pair of projecting, 

 spinnerets beneath the mouth, but uniting and drying at once in a single 

 thread. The intelligence that leads the caterpillar next to bind securely 

 the enveloped leaf-stem to the twig by throwing band after band abou 

 it, and in the event of the twig being a delicate one and liable to be 

 broken off, then, in addition, securing the twig by the process above 

 mentioned to its parent stalk — can not fail of amazing you. Do you 

 think it simple instinct, working in one unvarying line inherited from its- 

 ancestors, and incapable of adapting itself to different or changed con- 

 ditions ? Then try the experiment that I once made, and learn your 

 error. When all of this preparatory work has been completed, each 

 lashing examined over and over again, and finally pronounced all right 

 by its artificer — then with a sharp blade of your knife, quietly and neatly 

 sever the leaf-stalk just where it is bound to the twig and, replacing it 

 with accurate adjustment, insert a fine insect pin to hold it in place. 

 You will not have long to wait before the spinning of the cocoon will be 

 arrested and a reconnoitering expedition commenced. Your treacherous 

 work is discovered as soon as the point is reached. The situation is at 

 once taken in — the danger, the necessity of meeting it, and how best to 

 do it, fully comprehended. You may not read in the microscopic eyes of 

 the caterpillar, the successive phases of anxiety, alarm, distrust, annoy- 

 ance, anger, resolve, triumph, but you may see him apply himself to the 

 task of lashing anew the foot-stalk to the twig and thus bid defiance to 

 your perfidious pin, around which he throws his silken threads, until the 

 severed stem is stronger than before. What else is this than reason ! 



The shaping and formation of the cocoons will be of interest to watch, 

 until the thickening walls have hidden the larva from your view. During 

 the winter, you may sacrifice one or more of the number by making 

 sections of them, that you may observe the structure of the double 

 cocoon — ■ one within the other, with the intermediate loosely-threaded 

 non-conducting air-chamber, and the contained pupa, with its wing, leg^ 

 and antennge-cases folded upon its breast, and the cast-oft" caterpillar 

 skin compacted in a pellet behind it. 



Your study of this life-history will not be fully carried out to its proper 

 completion until, in the following spring, you can see the moth emerge 

 from its cocoon. A strange looking object will it seem in your eyes, as 

 with a brisk movement of its legs, it clambers upward to some position 

 where its unexpanded wings may hang downward, limp and wet, over its- 



