No. 7. DEPARTMENT OF AGRICULTURE. 223 



iiig the French with the English mutton sheep, then he found that 

 by crossing or breeding together different varieties of French sheep 

 tliat resembled each other quite closely, that he secured a sheep dif- 

 fering in many respects. These he crossed with the English sheep, 

 and got the desired result at once. He broke up this long line 

 of uniform ancestry by breeding these three or four breeds of French 

 sheep together, then he got good mutton sheep from the English 

 bred sires. 



In order to induce great variation there must have been a mixed 

 ancestry. Variation does not come from a long line of uniform 

 ancestry, but from ancestry that is greatly varied, particularly in 

 the recent generations. Just in proportion as the breeding is 

 mixed, whether in animals or plants, so is the tendency to uniform 

 production lessened. It is also a fact that the male leads in varia- 

 tions. We see indications of variation or variations in the male, and 

 Vie usually see variation first in the organs that pertain particularly 

 to the male. In poultry, for instance, those organs that are peculiar 

 to the cock will be found to be more largely developed than in the 

 female, as in the comb, or wattles, and we should expect to see varia- 

 tion first in the male. It is thought that the female, in many of our 

 domesticated species, has changed somewhat less from the wild form 

 than has the male. Physiologists also tell us that monstrosities 

 are more likely to be observed in the male sex, also that there are 

 more likely to be male idiots than female. 



In these few words I have tried to state a few of the conditions 

 which tend to make heredity strong and also those which tend to 

 make variation strong, or to induce variation. Now that we may see 

 the application of this a little more clearly, I would like to discuss 

 with you for a few minutes the principle of crossing, or cross-breed- 

 ing. I may say that this term is often used rather loosely which leads 

 to a great deal of confusion. In its strict sense, cross-breeding of 

 course would mean the mating of animals of distinct breeds or spe- 

 cies; that is, crossing the breed. Nature seems to impose a bar- 

 rier on crossing species, although man has done this successfully 

 in some instances, but he always has to pay the penalty, 

 as nature imposes a penalty in crossing, particularly those 

 species that are very unlike. Species as a rule will not cross, but 

 if they do cross-breed, the progeny are not as strong and vigorous 

 as the progeny of either breed, particularly after the first 

 generation. The most natural attempt for a man to improve 

 his stock is, to cross it with animals having the desired char- 

 acteristics. Many men have attempted to do that and where the 

 cross has not been very marked — where the animals have not been 

 very unlike he has succeeded admirably. This may result benefi- 

 cially, or it may result in great harm; it depends upon the breeds 

 thus crossed or the mating through which the improvement is sought. 



