122 



ON THE BONES, ET€. 



tive,but always skilful, has introduced into the structure and arrangement 

 of the teeth of animals, or the organs that are meant to supply their place. 



The SKIN AND ITS APPENDAGES offer an equal diversity, and constitute 

 the next subject of our inquiry. 



All living bodies, whether animalor vegetable, are furnished with this in- 

 tegument : in all of them it is intended as a defence against the injuries to 

 which, by their situation, they are commonly exposed ; and in most of 

 them it also answers the purpose of an emunctory organ, and throws off 

 from the body a variety of fluids, which either serve by their odour to distin- 

 guish the individual, or are a recrement eliminated from its living materials. 



This integument accompanies animals and vegetables from their first 

 formation : it involves equally the seed and the egg ; and possessing a 

 nature less corruptible than the parts it encloses, often preserves them un- 

 injured for many years, till they can meet with the proper soil or season 

 for their healthy and perfect evolution. 



This is a curious subject, and must not be too hastily passed over. 

 After fish-ponds have been frozen to the very bottom, and all the fishes 

 contained in them destroyed ; or after they have been completely emptied, 

 and cleared of their mud ; eels and other fishes have been again found in 

 them, though no atteinpt has been made to re-stock the ponds. Whence 

 has proceeded this reproduction ? Many of the ancient schools of philoso- 

 I)hy, and even some of those of more modern date, refer us to the doctrine 

 of spontaneous generation, and beheve that they have here a clear proof of 

 its truth. But this is to account for a difficulty by involving ourselves in 

 one of a much greater magnitude. It is a petitio principii which we stand 

 in no need of, and which we should be careful how we concede. The 

 reproduced fishes have alone arisen from the ova of those which formerly 

 inhabited the fish-pond ; and which, from some cause or other, had sunk 

 so deep into the soil, as to be beyond the germinating influence of the 

 warmth and air contained in the supernatant water, communicated to it 

 by the sun and the atmosphere. But the indestructible texture of the in- 

 tegument which enclosed the fecundated ova has preserved them, perhaps 

 for years, from injury and corruption ; and they have only waited for that 

 very exposure to light, air, and warmth, which the removal of the superior 

 stratum of mud has produced, to awaken from their dormant state into 

 life, form, and enjoyment ; and but for which they would have remained 

 in the same state, dormant but not destroyed, for ten or twelve times as 

 long a period. 



So, in the hollows upon our waste lands, when they have been for some 

 time filled with stagnant water, we not unfrequently find eels, minows, and 

 other small species of the carp genus, leeches* and water insects, and 

 wonder how they could get in such a situation. But the mud which has 

 been emptied out of the preceding fish-pond has perhaps been thrown into 

 these very hollows ; or the ova of the animals have been carried into the 

 same place by some more recondite cause ; and they have been waiting, 

 year afl;er year, for the accidental circumstance which has at length ar- 

 rived, and given them the full influence of warmth, water, light, and air. 



The ova of many kinds are pecuharly fight, and almost invisibly minute. 

 They are hence, when the mud, which has been removed from fish-ponds, 

 becomes dry and decomposed into powder, swept by the breeze into the 

 atmosphere, from which they have occasionally descended into the large 



* S!ee Wild. p. 120- note, 



