Ohap. XiV. I:NHERITANCE : FIXEDNESS OF CHARACTER. 37 



CHAPTER XIY. 



INllERITAXCE continued — FIXEDNESS OF CHARACTER — PREPOTENCY 

 SEXUAL LIMITATION — CORRESPONDENCE OF AGE. 



FIXEDNESS OF CHAEACTER APPARENTLY NOT DVE TO ANTIQUITY OF INHERI- 

 TANCE—PREPOTENCY OF TRANSMISSION IN INDIVIDUALS OF THE SAME 

 FAMILY, IN CROSSED BREEDS AND SPECIES ; OFTEN STRONGER IN ONE 

 SEX THAN THE OTHER ; SOMETIMES DUE TO THE SAME CHARACTER 

 BEING PRESENT AND VISIBLE IN ONE BREED AND LATENT IN THE OTHER 

 — INHERITANCE AS LIMITED BY SEX — NEWLY-ACQUIRED CHARACTERS IN 

 OUR DOMESTICATED ANIMALS OFTEN TRANSMITTED BY ONE SEX ALONE, 

 SOMETIMES LOST BY ONE SEX ALONE — INHERITANCE AT CORRESPONDING 

 PERIODS OF LIFE — THE IMPORTANCE OF THE PRINCIPLE WITH RESPECT 

 TO EMBRYOLOGY ; AS EXHIBITED IN D03IESTICATED ANIMALS : AS 

 EXHIBITED IN THE APPEARANCE AND DISAPPEARANCE OF INHERITED 

 DISEASES; SOMETIMES SUPERVENING EARLIER IN THE CHILD THAN IN 

 THE PARENT — SUMJIARY OF THE THREE PRECEDING CHAPTERS. 



In tlie last two chapters tlie nature and force of Inheritance, 

 the circumstances which interfere with its power, and the 

 tendency to Ee version, with its many remarkable contingen- 

 cies, were discussed. In the present chapter some other 

 related phenomena will he treated of, as fully as my materials 

 permit. 



Fixedness of Character. 



It is a general belief amongst breeders that the longer any 

 character has been transmitted by a breed, the more fully it 

 will continue to be transmitted. I do not wish to dispute the 

 truth of the proposition that inheritance gains strength 

 simply through long continuance, but I doubt whether it can 

 be proved. In one sense the proposition is little better than 

 a truism ; if any character has remained constant during many 

 generations, it will be likely to continue so, if the conditions 

 of life remain the same. So, again, in improving a breed, if 

 care be taken for a length of time to exclude all inferior 

 individuals, the breed will obviously tend to become truer, 

 as it will not have been crossed during many generations by 

 an inferior animal. We have previously seen, but without 



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