SPHINX. BOMB YX. 



49 



22. The type of this family is the genus Sphinx, so called, because 

 sometimes the attitude of its caterpillar resembles that of the sphinx 

 of fable ; they fly with great rapidity and hover above flowers. 



23. The largest species in France is the Sphinx atropos, so 

 named, in consequence of a spot on the back resembling some- 

 what a death's head. Its caterpillar is yellow with blue stripes 

 on the side ; it lives on the potatoe-vine, jasmin, &c., and changes 

 to a nymph, about the end of August ; the perfect insect appears 

 in September. 



24. The NOCTURNAL LEPIDOP'TER^E always have horizontal 

 or inclined wings when in repose ; the superior wings are almost 

 always retained against the inferior (fig- 47) ; in this respect they 

 resemble the crepuscular lepidop'terae, but are distinguished from 

 them by their antennae, which diminish in size from the base to 

 the point, or in other words, they are seta'ceous. These lepidop'- 

 terae, which are sometimes called phaloense, ordinarily fly only at 

 night or in the evening after sunset ; in some species the females 

 are without wings, or have them very small. % Their chrysalids 

 are almost always round and lodged in a cocoon. 



This family is very numerous, and is divided into several tribes ; 

 the most interesting is that of the Bom'byces, which have inclined 

 wings, forming a triangle with the body. 



25. The mulberry bombyx 

 Bombyx mori (fig' 47) 

 of all insects is the most in- 

 teresting, because its caterpil- 

 lar, known under the name of 

 silk-worm, furnishes us with 

 silk. In the perfect state, this 

 butterfly is whitish, with two 

 or three darkish transverse 

 stripes, and a cross-like spot 



on the superior wings. Its caterpillar (fig. 48) has a smooth 



body, and at birth scarcely 



exceeds a line in length ; 



but attains in time to even 



more than three inches long. 



In this form the silk-worm 



Fig. 47. BOMBYX. 



lives about thirty-four days, 

 andduringthis timechanges 



Fig. 48. SILK-WORM. 



22. What is a Sphinx ? 



23. How is the caterpillar of the Sphinx atropos characterized ? 



24. How are the Nocturnal Lepidop'terze distinguished ? What are their 

 habits ? 



25. What are silk-worms ? What are the characters of the bombyx 

 mori? What are the habits of its larva? What is the colour of its 

 cocoon ? 



