THE CAUSATION OF DISEASE. 75 



It often happens that there is a " pre-potency " of some charac- 

 teristic or characteristics of one of the parents in the offspring, 



"When individuals belonging to the same family, but distinct 

 enough to be recognized, or when two well-marked races, or two 

 species are crossed,, the usual result .... is, that the offspring in the 

 first generation are intermediate between the two parents, or resemble 

 one parent in one part and the other parent in another part. But 

 this is by no means the invariable rule; for in many cases it is 

 found that certain individuals, races, and species, are preponent in 



transmitting their likeness It would appear that in certain 



families some one ancestor, and after him others of the same family, 

 have had great power in transmitting their likeness through the 

 male line; for we cannot otherwise understand how the same features 

 should so often be transmitted after marriages with many females, as 

 in the case of the Austrian emperors ; and so it was, according to 

 Niebuhr, with the mental qualities of certain Roman families. The 

 famous bull, Favourite, is believed to have had a preponent influence 

 on the short-horned race. It has also been observed with English 

 race-horses, that certain mares have generally transmitted their own 

 character, whilst other mares of equally pure blood have allowed 

 the character of the sire to prevail. A famous black greyhound, 

 Bedlamite, as I hear from Mr. C. M. Brown, ' invariably got all his 

 puppies black, no matter what was the cr. 1 our of the bitch ; ' but then 

 Bedlamite has a preponderance of black in his blood, both on the 

 sire and dam's side." — Variation under Domestication, vol. ii. p. 40. 



Again, Quatrefages writes : — 



"After having attributed a prepondering action to the 

 mother, Nott declares with surprise that in point of intelligence 

 the mulatto (negro and white) approaches in character to his 

 white father." * He goes on to observe that Lislet Geoffrey, 

 though entirely a negro physically, was in character and in- 

 telligence entirely a white. 



The above quotations on pre-potency seem to invalidate my 

 remarks on the structural mean. Be it noted, however, I am 

 careful to say a certain mean, and not the exact mean. From 

 the time the ovum and spermatozoon meet, until development is 

 complete, or perhaps even later than this, there is a struggle 

 between two tendencies : the tendencies of the ovum will gain 



* International Science Series, Quatrefages, p. 268. 



