226 POPULAR SCIENCE MONTHLY. 



tive type have ceased to operate. A similar effect is produced in 

 those cases in which a given variation appears accidentally in a 

 single individual and is then transmitted to his offspring. ... In 

 other words, a permanent variety is likely to arise." In the Origin 

 of species, Chapter I, in speaking of variations, Darwin says: 

 " We are driven to conclude that this great variability is due to 

 our domestic productions having been raised under conditions of 

 life not so uniform as, and somewhat different from, those to which 

 the parent species had been exposed under Nature. " The same idea 

 is here expressed in somewhat different words, and Darwin's notion 

 as to the transmission of such peculiarities by heredity is too familiar 

 to be repeated. 



As an illustration of the law thus laid down, Cabell cites the well- 

 known story of the origin of the Ancon or Otter sheep from a 

 spontaneous variation occurring in the flock of Seth Wright in Mas- 

 sachusetts; and it may be remembered that Huxley uses the same 

 incident in the same relation, but without reference to its previous 

 use by Prichard and Cabell. As further evidence, he brings for- 

 ward the changes arising in the horses and cattle that were brought 

 to this continent as domesticated animals, but escaped into the 

 forests and plains, and shows that without admixture— for these 

 animals are not indigenous — varieties arose differing from the parent 

 stock so markedly as to constitute new species. On the other hand, 

 he shows that the hog, an exotic animal brought here under domes- 

 tication, reverted to the primitive stock. So striking is this that it 

 will repay copying in full (page 31): 



" The hog is known not to be indigenous to this country, but 

 was introduced into St. Domingo at the first discovery of that island 

 in 1493, and successively to all the places where the Spaniards 

 formed settlements. These animals multiplied with great rapidity 

 and soon invested the forests in large herds. At length, under the 

 influence of their wild state, they have resumed the characters of 

 the original stock — that is, their appearance very closely resembles 

 that of the European wild boar, from which the domesticated breeds 

 have sprung. Their ears have become erect, their heads are larger, 

 and their foreheads vaulted at the upper part; their color has lost 

 the variety found in the domestic breeds, the wild hogs of the 

 American forests being uniformly black. The hog which inhabits 

 the high mountains of Paramos bears a striking resemblance to the 

 wild boar of France. His skin is covered with thick fur, often some- 

 what crisp, beneath which is found in some individuals a species of 

 wool. Thus the restoration of the original characters of the wild 

 boar, in a race known to have sprung from domesticated swine 

 brought over to America by the Spaniards, removes all reason for 



