410 LECTURE XIV. 



finally conducive to a permanently altered type. But this 

 circumstance, that for the formation and permanency of 

 natural races and species, a long period of time is requisite, 

 leads us back to the consideration of a question which occupies 

 a prominent position in artificial breeding. The breeders still 

 debate whether age, constancy, and jDurity of blood are the essen- 

 tial elements in transmission, or whether the quality of the in- 

 dividual be not the predominating agent. Since even accidental 

 defects, supernumerary fingers, arrest of development, are 

 transmitted and persistent through several generations, it 

 appears that individuality stands in the first rank. Never- 

 theless the length of time during which a race has maintained 

 itself is of the greatest importance, as the probability of trans- 

 mission is greater in proportion to the purity of blood and 

 the duration of the race. This is proved by the influence of 

 grandparents, which, is so strikingly manifested. When it is 

 said that the influence of th.e grandparents upon the grand- 

 children is essentially an indirect one, the assertion is too 

 restricted in jDresence of the fact that frequently the grand- 

 children exhibit qualities possessed by the grandparents only 

 and not by the parents. One of my friends has a bitch of the 

 St. Gothard breed, which, excepting a narrow white spot 

 upon the chest, is perfectly black. Two brothers of this bitch 

 were spotted light brown. The mother was black, the father 

 yellowish-brown. The bitch, having been covered by a perfectly 

 black dog of the same race, produced a litter of five puppies, 

 three of which Avere black with white spots upon the chest, 

 and two with yellowish-brown spots like the grandfather. The 

 peculiarity of the grandfather was here not transmitted to the 

 child but to some of the grandchildren. If cases of this kind 

 are authenticated, and I can vouch for this one, as I possess one 

 of the puppies, and have seen the mother and the brothers, then 

 it is clear that even in the purest blood there are sometimes re- 

 lapses to the ancestral stock, the qualities of which are deemed 

 extinct, and that, on the other hand, natural races and 

 species maintain their characters even in crossings with great 

 pertinacity, so that they may re-appear in succeeding genera- 

 tions. Thus all dog-breeders know that the blood of a New- 



