98 



ON CEOSSING AS A CAUSE 



Chap. XV. 



and with some white spots at the base of the beak ; so that bv 

 the aid of a little selection a new breed might easily have been 



form ed 



In regard to crossed varieties of plants, Mr. B 



remarks 32 that " Melville 



Scotch kale and an early cabbage is as true and g 



y cross between the 



on record ; " 

 Gartner 33 h 



b 



case 



five 



kept constant; and hyb 



remained 

 Dr. Herbert likew 



doubt selection was practised, 

 of hybrids, in which the progeny 



veen Dianthm armeria and 



bet 



and uniform to the tenth 



g 



rise showed me a hybrid from two species of 

 Loasa which from its first production had kept constant durii 



alg 



\^ 



have seen in the earlier chapters, that some of our 



domesticated animals, snch as dogs, cattle, pigs, &c 



tainly descended from 



than 



one species; or wild 



if any one prefers to apply this latter term to forms which 



enabled to keep distinct in a state of 



Hence the 



Kutimey 



of aboriginally distinct species probably came into play 

 ly period in the formation of our present races. 



Fr 



obse 



there can be little doubt 



ed with cattle : but in most cases some one of the 



which were allowed to cross freely 

 absorbed and obliterated the others. 



all, it is probable, kav 

 For it is not likely the 



semi-civilized men would have taken the 



7 



their commingled, crossed, and fluctuati 



modify by selection 

 stock. Nevertheless, those animals which were best adapted to 

 their conditions of life would have survived through natural 

 selection ; and by this means crossing will often have indirectly 

 aided in the formation of primeval domesticated breeds 





W 



recent tim 



as far as animals are 



ed, the 



g of distinct species has done little or 



■g 



in 



formation or modification of 



races. It is not yet 



whether the species of silk-moth which have been r 



tly 



crossed in France will yield permanent races. In the fourth 

 chapter I alluded with some hesitation to the statement that a 

 new breed, between the hare and rabbit, called leporides, had 

 been formed in France, and was found capable of propagating 



32 i 



Cottage Gardener,' 1856, p. 110. 



33 ' Bastarderzeusrung,' s. 553. 



