BREEDS AND THEIR MODIFICATIONS. 25 



sales because the breeders have followed features which the foreign 

 buyer has specially called for. Another point which requires 

 more recognition is that as a breed is taken further from the con- 

 ditions indigenous to it, as where food is produced on the land of a 

 different character to that which developed the indigenous features, 

 the sheep will tend to alter, being influenced by the new conditions. 

 Sheep for centuries fed on grass are sure to modify when roots 

 and other cropping form a great portion of their food, and when, 

 for many generations, they have in addition a large quantity 

 of cake or other concentrated food, they are likely to lose more 

 of their indigenous features. As all breeds have intermixture 

 of blood, the sheep will tend to follow the features of the component 

 breeds which appreciate or are most influenced by the change of 

 food. Breeds ought not to stand still, but they need to be steered 

 carefully. The breeder has not merely to think how it looks, 

 but rather to consider what it is and what it will do. 



For some years special attention has been paid to the principles 

 of breeding set out by Mendel, and Professor Wood, of Cambridge, 

 carried out some very interesting experiments on sheep, showing 

 how it was possible to cross breeds of great antagonism in 

 feature to breed new types giving them fixity of feature, and 

 to a considerable extent of characteristics. However, breeding 

 must be a work of a very exhaustive nature if an attempt is made to 

 take full advantage of new principles and time and opportunities 

 have not offered this at present. With such new breeds it has yet 

 to be discovered how the indigenous forces of soil, climate, elevation, 

 food, &c., will modify them in the course of years. The destruction 

 of cells controlling certain growths may, as far as can be reasonably 

 argued, be so completely effected that they cannot be redeveloped 

 whilst breeding in true lines is followed, and thus objectionable 

 features may be eliminated ; but at present we lack knowledge 

 as to how the unaffected cells would be influenced. They might 

 or might not be affected unduly by natural surroundings, though 

 there seems no reason why selection should not keep these corrected, 

 as such things are controlled by selection as it has been carried 

 out hitherto. One can see considerable possibilities in its connection 

 with sheep breeding and improvement, but apparently what is done 

 until the principle is subjected to much more investigation will 

 have to be regarded as experimental. 



