G. GENERAL NATURAL HISTORY AND ZOOLOGY. 187 



men recalls very vividly the peculiar condition of the hoof in 

 the extinct genus Hipparion, which, according to many writ- 

 ers, is one of the original ancestors of the genus to which the 

 modern horse belongs. 12 A, November 16, 394. 



VISION OF THE YOUNG MOLE. 



It is a fact well known to naturalists that in many cases 

 where a full-grown animal is marked by the absence of cer- 

 tain organs or appendages found in the majority of its class, 

 they exist in a normal condition in the fetal stage. This is 

 shown in the occurrence of teeth in the jaws of the young- 

 whale (which are totally wanting after birth), the incisor 

 teeth of the fetal rodent, the existence of eyes on both sides 

 of the head in the young flounder, etc. A new instance of 

 this general principle has been recently announced in regard 

 to the European mole, the adult of which is usually consid- 

 ered to be blind. The fetal mole, however, according to Mr. 

 Lee, in a late paper, is endowed with organs of vision, which 

 at the time of birth are of considerable perfection, but in ad- 

 vancing age certain changes take place in the base of the 

 skull, which terminate in the destruction of the most impor- 

 tant structures on which the enjoyment of the sense of sight 

 depends. 5 A, October, 1810, 446. 



NEW-BORN HIPPOPOTAMUS. 



The female hippopotamus at the Zoological Gardens of 

 London not long since gave birth to a young one, which, we 

 regret to say, died a few days afterward, making the eighth 

 case in which births of this animal have occurred in Europe 

 all of them dying, with a single exception, before reaching 

 maturity. This one, born in Amsterdam, was almost equally 

 unfortunate, as it was destroyed many years ago at the burn- 

 ing of the Crystal Palace in New York. A post-mortem ex- 

 amination of the case first mentioned showed that it must 

 have had chronic peritonitis before birth, as its stomach and 

 liver were adherent to the peritoneum. 20 A, March 4, 253. 



DECIDUOUS NATURE OF THE RHINOCEROS'S HORN. 



The statement that the horn of the rhinoceros is deciduous, 

 or, at least, can be reproduced when accidentally lost, has 

 been confirmed lately at the Zoological Gardens in London. 



