THE EGG. 13 



7. Color. — The eggs of insects vary as widely in their 

 coloring as in their shape and sculpture. 



Often they are white, resembling minute pearls ; some, 

 as those of the silkworm, are of a beautiful golden yellow ; 

 others, as those of the bloody-nosed beetle (timarcha tene- 

 bricosa), of beautiful orange ; others, again, are of a golden 

 hue or a deep red, and of every intermediate shade ; 

 others are blue, green, speckled, striped, or banded with 

 zones of different colors. 



In general all these eggs are white when first laid, but 

 change and assume these various colors in a few days. 



8. Period or Hatching. — The kind of food the larva 

 is to feed on, and the temperature of the air, determine 

 the length of time required for the hatching of the eggs. 



The carnivorous insects ordinarily require the least time, 

 e. g., the eggs of many flesh-flies are hatched in twenty- 

 four hours, and they vary from that time up to nine 

 months, as required by several of the plant-eating insects, 

 as some of the butterflies ; besides, many of those kinds 

 that, in the heat of summer, require but a short period 

 for hatching, will remain unchanged through the colder 

 months of the year. 



Most insects depend merely upon the heat of the sun 

 for the hatching of their eggs, though many species make 

 special provision for this by laying their eggs in heat- 

 producing places, such as heaps of decaying vegetable 

 mould, barnyard refuse, or even in the bodies of other 

 living animals. 



