304 LONGEVITY OF ANIMALS. 



knew it ; but when I was first acquainted with it, he used to 

 mention it as the old toad I have known so many years : I can 

 answer for thirty-six years." " In respect to its end, had it 

 not been for a tame raven, I make no doubt it would have 

 been now living, who, one day seeing it at the mouth of its 

 hole, pulled it out, and though I rescued it, pulled out one 

 eye, and hurt it so, that, notwithstanding its living a twelve- 

 month, it never enjoyed itself, and had a difficulty in taking 

 its food, missing the mark, for want of its eye. Before that 

 accident it had all the appearance of perfect health." 



Most Insects, especially after their last transformation, are 

 short-lived. But the species are continually supported by their 

 wonderful fecundity. Those animals whose parts require a 

 long time of hardening and expanding, are endowed with a 

 proportional degree of longevity. Insects grow and their 

 bodies harden more quickly than those of larger animals. 

 Many of them complete their growth in a few weeks, and 

 even in a few days. The duration of their existence is ac- 

 cordingly limited to very short periods. Some species of 

 flies lie in a torpid state during the winter, and revive when 

 the heat of spring or summer returns. The ephemeron flies, 

 of which there are several kinds, seldom live above one day, 

 or one hour, after their transformation. But to continue the 

 species, nature has taken care that myriads of males and 

 females should be transformed nearly at the same instant. 

 Other kinds are transformed more irregularly, and live several 

 days. Here the wisdom of nature is conspicuous ; she pro- 

 longs the existence of these animals for no other purpose but 

 to make provision for the continuance of the species. Bees, 

 and flies of all kinds, after lying long in the water, and having 

 every appearance of death, revive by the application of a 

 gentle heat, or by covering their bodies with ashes, chalk, or 

 sand, which absorb the superfluous moisture from their pores. 

 Reaumur made many experiments upon the reviviscence of 

 drowned bees. He found, that after being immersed in water 

 for nine hours, some of them returned to life; but he ac- 

 knowledges that many of them, in the fourth part of this time, 

 were actually dead, and that neither heat nor the application 

 of absorbent powders could restore them to life. Analogical 

 reasoning is often deceitful, but it frequently leads to useful 

 truths. As flies of all kinds, after immersion in water, and 

 exhibiting every mark of actual death, can be restored to life 

 by covering their bodies with any absorbent substance, with- 

 out the assistance of a heat superior to that of the common 



