Chap. 74.] QENEEATION OF TISHES. 463 



to be distinguished by the eyes and tail ; very soon, how- 

 ever, the feet are developed, and the tail, becoming bifurcate, 

 forms the hind legs. It is a most singular thing, but, after a 

 life of six months' duration, frogs melt away" into slime, 

 though no one ever sees how it is done ; after which they come 

 to life again in the water during the spring, just as they were*" 

 before. This is effected by some occult operation of Naturej 

 and happens regularly every year. 



Mussels, also, and scallops are produced in the' sand by the 

 spontaneous^ operations of nature. Those which have a harder 

 shell, such as the murex and the purple, are formed from a 

 viscous fluid like saliva, just as gnats are produced from liquids! 

 turned sour,^ and the fish called the apua,*'' from the foam of 

 the sea when warm, after the fall of a shower. 



Those fish, again, which are covered with a stony coat, such 

 as the oyster, are produced from mud in a putrid state, or elses 

 from the foam that has collected around ships which have been 

 lying for a long time in the same position, about posts driven 

 into the earth, and more especially around logs of wood."' It 

 has been discovered, of late years, in the oyster-beds,'' that 



shoot out at the hase of the taU, and in the same proportion that they grow, 

 the tail decreases, till at last it entirely disappears. 



^ Frogs, Cuvier says, conceal themselTes in mud and slime during the 

 winter, hut, of course, are not changed into it. 



** " Quae fuere." just in the same state, he probahly means to say, in 

 which they were when they were melted into sfime, and not as they were 

 when in the tadpole state. 



^ All that is asserted here, Cuvier says, about the spontaneous opera- 

 tions of nature is totally false. Everything connected with the eggs and 

 the generation of the mussel, the murex, and the scallop is now clearly 

 ascertained. 



8' "Acescente humore." Hardouin has suggested that the proper 

 reading may he " arescente humore" — " from moisture dried up ; " for, he 

 remarfi, Aristotle, in his Hist. Anim. B. t. c. 18, states, that the 

 " empides," gnats formed from the aacarides in the slime of wells, are 

 more frequently produced in the autumn season. 



s'* The apuse, or aphyae, Cuvier says, are nothing else but the fry offish 

 of a large kind. 



'* Cuvier says, that some of the shell-fish deposit their eggs upon stakes 

 and piles, which are driven down into the water among sea- weed, and the 

 bottoms of old ships : but that many of them perish from the solutions 

 formed by those bodies in a state of rottenness, or, at all events, are not 

 produced from their decomposition. 



89 " Ostreariis." This was unknown to Aristotle, who, in his work De 

 Gener. Anim. B. iii. c. 11, expressly denies that the oyster secretes any 

 generative or fecundating liquid. 



