EXPERIMENTS ON SELECTION 239 



of the variation. On this point I shall merely refer 

 those who desire more information to Darwin's book 

 on variation : instances are there most numerous and 

 convincing, as concerns animals and plants, and are 

 enough to show the power of selection. I may also 

 refer to some recently-noticed cases. One con- 

 cerns the production of a new variety of hornless 

 oxen. In 1874 a Sicilian farmer noticed among his 

 herd a young bull which had no horns at all. This 

 young bull was allowed to mate, and the result has 

 been the production of other hornless animals, so that, 

 by selecting at each generation the progenitors of the 

 following this farmer has obtained a hornless variety. 

 A similar fact occurred in 1 86 1 in a village of the 

 Mouse department. A cow gave birth to twins, male 

 and female, deprived of horns : they were mated 

 together, and thus, by constant selection of hornless 

 animals as progenitors, a hornless variety has been 

 also created. The breed of Mauchamp sheep has 

 similarly been evolved out of a ram which was born in 

 1828, in the Mauchamp farm, with the peculiarity of 

 bearing an even wool, instead of having it frizzled, 

 merino-like. And M. Cornevin, from whose work I 

 abstract these facts remarks that any day any 

 breeder in the south of France can, if he chooses, pro- 

 duce by simple selection a variety of sheep with four 

 udders, for these animals often bear four of these 



