346 INSECT TRANSFORMATIONS. 



on which its caterpillar feeds. Rdaumur, who liad 

 never found the caterpillar, thought that so delicate 

 an insect could not exist out of doors during the bleak 

 weather of spring ; and concludes that it feeds like 

 the clothes-moth in-doors — an instance among hun- 

 dreds more how frequently our most plausible reason- 

 ings are far removed from the facts. This moth is so 

 small that it is not ready to catch the eye of those who 

 are unacquainted with it, and even when it is found 

 it requires a magnifying glass to perceive all its 

 beauties. 



The movements of insects just escaped from the 

 chrysalis appear, then, to be analogous in their design 

 to the restless motions of the young of larger animals. 

 In Darwin's fanciful language, the accumulation of 

 excitability in the sensorium impels the creature to 

 be frisky for the purpose of getting rid of the super- 

 abundant stimulus ; but whatever the exciting cause 

 may be, we are certain that the final cause and certain 

 effect is the brisker impulsion of fluids, and particu- 

 larly air, through the vessels appropriated to their 

 circulation, and consequently the more perfect nou- 

 rishment and speedy growth of the several members. 

 The analogy between the larger animals and insects 

 is, that the latter, when they have undergone their 

 last change from the pupa into the perfect insect, 

 never increase in size, as the former remain stationary 

 soon after puberty. 



We notice this the more readily, as those who are 

 but little acquainted with insects are exceedingly 

 apt to think they grow like other animals, and from 

 this cause commit many mistakes, not perhaps of 

 great moment, but which in a work like this it may 

 prove interesting to rectify. " The most common 

 British butterflies," it has been remarked, " most 

 persons may have observed to be those which are 

 white; and all these are usually looked upon as 



