60 INHERITANCE. Chap. XTV. 



prepotent over the other in transmitting its character. A 

 race may possess a strong power of inheritance, and yet when 

 crossed, as we have seen with trumpeter-pigeons, yield to the 

 prepotency of every other race. Prepotency of transmission 

 may be equal in the two sexes of the same species, but often 

 runs more strongly in one sex. It plays an important part 

 in determining the rate at which one race can be modified or 

 wholly absorbed by repeated crosses with another. We can 

 seldom tell what makes one race or species prepotent over 

 another ; but it sometimes depends on the same character 

 being present and visible in one parent, and latent or poten- 

 tially present in the other. 



Characters may first appear in either sex, but oftener in 

 the male than in the female, and afterwards be transmitted 

 to the offspring of the same sex. In this case we may feel 

 confident that the peculiarity in question is really present 

 though latent in the opposite sex ! hence the father may 

 transmit through his daughter any character to his grandson ; 

 and the mother conversely to her granddaughter. We thus 

 learn, and the fact is an important one, that transmission and 

 development are distinct powers. Occasionally these two 

 powers seem to be antagonistic, or incapable of combination 

 in the same individual ; for several cases have been recorded 

 in which the son has not directly inherited a character from 

 his father, or directly transmitted it to his son, but has 

 received it by transmission through his non-affected mother, 

 and transmitted it through his non-affected daughter. Owing 

 to inheritance being limited by sex, we see how secondary 

 sexual characters may have arisen under nature ; their 

 preservation and accumulation being dependent on their 

 service to either sex. 



At whatever period of life a new character first appears, it 

 generally remains latent in the offspring until a corresponding- 

 age is attained, and then is developed. When this rule fails, 

 the child generally exhibits the character at an earlier period 

 than the parent. On this principle of inheritance at corre- 

 sponding periods, we can understand how it is that most 

 animals display from the germ to maturity such a marvellous 

 succession of characters. 





