168 



CANADIAN FARM YEAR BOOK. 



in a high degree ds a verltalble bon- 

 anza; naturally the temptation Is to 

 nmke the most of an opportunity 

 which is none too frequent ia the 

 breeding business. 



All things considered, no otiher 

 known method of breeding equals this 

 for intensifying blood lines, doubling 

 uip existing combinations, and making 

 the most of exceptional individuals or 

 of xmusually valuable strains. 



Disadvantages of Inbreeding. 



Clearly, however, this is not a gun 

 to "hit the bear and miss the calf." 

 This "doubliug up" process, this inten- 

 BifyitLg of characters, increasing their 

 prospects from possibility to proba- 

 bility and afterward to certainty, 

 works exactly the same for one char- 

 acter as for another; it affects all 

 characters of the individuals invodved, 

 bad as well as good; and so it is that 

 this method, which is applicaible to 

 both plant and animal 'breeding, and 

 which aims at making tihe greatest use 

 possible of our most valuable imsses- 

 sions, has been followed alike by tlhe 

 most strikingly successful results 'and 

 by the most stupendous disasters that 

 ever overtook the (breeding business. 

 Plenty of examples of successes can 

 be instanced, and every breeder Is 

 familiar with them. The failures have 

 been many, but they are not to be 

 counted here, for the blood lines in- 

 volved are long since extinct. 



Special Dangers From Inbreeding. 



Tradition eveiywhere has it that in- 

 Tbreeding, if long continued, is practi- 

 cally certain to end in loss of vigor 

 and of fertility, and plenty of in- 

 stances are given to "prove" it. 



Now a rational consideration of the 

 principles of transmission has already 

 led us to expect that bad characters 

 OS well as good will be intensified. We 

 could not axpeot so powerful a method 

 to work only to our advantage and to 

 grant Immunity from disadvantage in 

 all cases. 



What we want to know Is whether. 

 In resipect to trouble, we are to look 

 out for likelihood or for certainty; 

 whether disaster is inevitable, or only 

 extremely probable. This question 

 has been much befogged by certain 

 catdhy statements such as, "Nature 

 abhors Incestuous breeding," all oi 

 Which confuse an ethical and social 

 question with the biological one in 

 which only we are inter©s.tetf. 



Inbreeding Nbt Necessarily Disastrous. 



Our attention is constantly callod to 

 "nature's provisions for preventing in- 

 breediing," and to "ingenious devlcee 

 for inducing cross pollination by in- 

 sect aid"; but we are not reminded 

 that many species of plants are self- 

 pollinated, nor is our attention called 

 to the many famous sires that were 

 strongly inibred, nor to the fact that 

 in nature among gregarious animals 

 the head of the herd is sire of practi- 

 cally all the young (so long as he re- 

 mains master), m^any of whom are 

 thus doubly his. Nor do we have it 

 called to our attention that, while 

 corn seems peculiarly sensitive to in- 

 breeding, wheat is self-fertilizing to 

 the closest possible degree, and that 

 it is perhaps the most vigorous, proli- 

 fic, and all-round cosmopolitan success 

 among our domestic plants. 



Lack of Vigor and Low Fertility the 

 Two Most Common Defects. 



If what has been said and shown 

 has any meaning, it is that any char- 

 acter can be bred up or down, streng- 

 thened or weakened by this method of 

 Ibreeding. Why then its evil reputa- 

 tion with respect to vigor and fertil- 

 ity? Is there some Inherent injury 

 from close breeding, or is it merely 

 that vigor and fertility are commonly 

 defective characters and frequently 

 find themselves on the losing side? 

 Undoubtedly it is the latter. There 

 are cases enough of the greatest vigor 

 and fertility of inbred individuals, and 

 of family lines and even of whole 

 s.peoies to set aside all fear of inevit- 

 able injury from close breeding, but a 

 little study will convince us that there 

 is lurking weakness and infertility 

 everywhere. It is said that one-third 

 of our children die in infancy. A large 

 proportion of animals and an apparent- 

 ly larger proportion of plants are rela- 

 tively weak and easily succumb to 

 disease or to the encroachments of 

 their neighbors. 



Few individuals are fully fertile,— 

 that is, free and regular breeders, — 

 and fewer yet are both fertile and 

 vigorous. Shortcomings in these two 

 respects may be called the distinguish- 

 ing defects of both plants and animals 

 under domestication. In nature they 

 constitute the chief points of attack 

 of natural selection, but In domesti- 

 cated animals and plants we common- 



