THE JACKAL 181 



some will be wilder, others more submissive. The 

 first are rejected, the second kept, as soon as it is 

 possible to recognize this diversity of disposition. 

 Here, then, the sons, with, continued training, become 

 superior to the fathers. The same care, the same se- 

 lection, in the third generation, will insure increased 

 progress in the grandchildren. The acquired im- 

 provement will be transmitted by inheritance to 

 the great-grandchildren, these will still further add 

 to it, and it will be inherited by their descendants, 

 or, if not by all, at least by some. These latter will 

 be raised in preference to the others. However 

 slight the progress from one generation to the next, 

 it will continually be added to by the intervention of 

 man who always selects for breeding purposes the 

 most promising offspring, until, little by little, in 

 course of time the beast that was intractable in the 

 beginning at last becomes docile. 



' l This onward march, which is kept up by accumu- 

 lating in the animal, through inheritance, the quali- 

 ties desired, by always picking out the individual 

 possessing these qualities in the highest degree, is 

 called selection, meaning choice or sorting. The 

 method of selection, which to-day still renders the 

 greatest service to the perfecting of species, has 

 doubtless played an important part in the domestica,- 

 tion of the dog; but that alone is not what has made 

 the dog such as we now have him. The astonishing 

 variety of dogs can only be explained by the multi- 

 plex origin of the animal and the crossing of the va- 

 rious breeds. I have just told you of one species, the 



