RISE AND PROGRESS OF ZOOLOGY. li.U 



without the use of vision. They seem enabled 

 to perform this, by the delicacy of the sense of 

 touch spread over the enormous surface of their 

 ears and wings, and the extreme fineness of 

 their sense of hearing. 



The faculty of reproducing parts cut off, so 

 remarkable in the armed polypus, and so famous 

 from the experiments of Trembley, is not much 

 less strongly manifested in the actiniae, and 

 other zoophytes, according to the Abbe Dic- 

 quemare : its existence in the crab, has been 

 long known. From Spallanzani and Bonnet, we 

 learn to what a degree it extends in the aqua- 

 tic salamanders and snails. Broussouet has 

 proved that it is nearly as much extended as 

 in fishes. 



Bonnet had discovered in the pucerons, the 

 faculty of being fecundated for many genera- 

 tions by a single connexion. M. Irvine has ob- 

 served it carried still further, in certain of the 

 monoculi. 



The state of lethargy, more or less profound, 

 in which some animals pass the cold season, 

 is another property well worthy the attention 

 of the philosopher. This has given rise to the 

 most interesting discussions and researches, and 

 if we are not exactly acquainted with the 

 causes of so singular a phenomenon, we at 



