274 



The eggs were emptied upon a piece of moist blotting paper, covered 

 with glass and set in a warm place. A temperature of 60° F. is suffi- 

 cient to hitch them. The moisture serves to soften the shell and varnish. 

 The worm makes a perforation in the edge of the disk, and through this 

 opening its head can be seen vigorously gnawing at the tough rind which 

 imprisons it. Some larvse* make a meal of their entire egg-shell, de- 

 vouring what is left of it after they emerge, but these merely eat a hole 

 large enough to crawl through. They hatch early in the morning and 

 have the advantage in their natural state of a drink of dew before going 

 to the leaves. For this reason it is best to give them water before 

 placing them upon their food, or the twigs may be sprinkled with water. 

 They should never be touched by inexperienced fingers, but may be 

 lifted upon a soft brush. In handling them observe the fact that their 

 tendency is to crawl upwards. 



The length of the newly hatched worm is 7°^"\ The general color is 

 dark, and they are quite hairy. This appearance serves a useful pur- 

 pose, rendering them less conspicuous upon the twigs of the oak, and 

 much better protected from the sharp sight of insect-eating birds than 

 if they presented the bright green color of their later stage. 



The young worms when x^laced upon their food at once crawl to the 

 end of the stem and attack the leaves. In their first period they are 

 rather restless and disposed to wander, particularly if in a light i^lace. 

 In four or five days they attain the length of 14">"\ 



The caterpillar then prepares to cast its skin. For this it is neces- 

 sary that it should have a firm hold upon the twig, to secure which it 

 crawls away to the end of the stem and covers the bark for a short space 

 with a net- work of silk. Firmly grasping this fabric with its hinder 

 pairs of legs for two or three days, it composes itself to sleep while in- 

 ternal changes are taking place. During this sleep it does not assume 

 the ordinary position of rest. The fore part of the body is elevated and 

 very much drawn together, a position characteristic of the larva of the 

 SphingidcHe. 



Molting insects should never be disturbed. This change involves a 

 great strength, and sickly ones are unable to endure it. Those un- 

 fortunates who enter into the new period with portions of the old skin 

 still attached to them are quite likely to die. 



The newly molted worm looks pale and delicate. Its head, much in- 

 creased in size, is of a creamy color, the body of a light green and sparely 

 covered with thin hairs. The segments do not present the plump, 

 rounded appearance that is characteristic of the condition just before 

 the molt, but are angular. After a short rest it repairs to the ends of 

 the twigs where the leaves, which are now quite large and of a glossy 

 green, serve to relieve its hunger. The chief occupation of the worms 

 during the period between the molts is eating, and as the amount eaten 



The Spbingidii' 



