Chapter VII. 



Growth, Moiiltino;, Strength, Defence, and Hybernation of Larvs. 



From the facts being commonly known, we are not 

 surprised, that an ostrich, nine feet high and 150 lbs 

 weight, should be produced from an egg about the 

 size of a cocoa-nut, or that ' a grain of mustard-seed 

 — the least of all seeds — when it is grown,' should 

 become ^a tree {Plujiolacca dioi c a T), so that the 

 birds of the air come and lodge in the branches 

 thereof* But when similar facts are recorded by 

 naturalists respecting insects, general readers are apt 

 to wonder, because they are less familiar with these 

 details, than with the economy of trees springing from 

 seeds and birds being produced from eggs. When we 

 repeat, after Lyonnet, that the caterpillar of the goat- 

 moth {Cossiis ligmiperda, Fabr.) becomes 72,000 

 times heavier than when newly hatched,| we do not 

 state anything more striking and admirable than that 

 an embryo of small dimensions should become an ele- 

 phant, or that an acorn should produce a lofty and 

 magnificent oak. The facts respecting the growth of 

 insects have an adventitious interest, because, in con- 

 sequence of the minuteness of the objects to which 

 they relate, they are less familiar to popular observa- 

 tion. In the instance of the silk-worm, the progress 

 of growth has been accurately ascertained by scientific 

 cultivators. It appears that a single caterpillar, 

 weighing when first hatched only the hundredth part 

 of a grain, consumes in thirty days above an ounce of 

 leaves, — that is to say, it devours in vegetable sub- 



* See Irby and Mangle's Travels, letter v. 

 t Traite Anat. de la Chenille, p. 11. 



