MENTAL AND MORAL HEREDITY IN ROYALTY. 427 



families have done. Some exceptions to this may occur, as among 

 the descendants of Jonathan Edwards and the famous musician, Bach, 

 but in these cases the mental qualities were perpetuated. 



In the lower forms of animal life we know by actual experimenta- 

 tion that slight changes in the environment occasion the greatest dif- 

 ference in results, still in spite of the strange modifications that may 

 be occasioned in the developing fish or frog by external mechanical 

 or chemical means, the question resolves itself under ordinary conditions 

 to the nature of the primary germ-cells. 



If a naturalist were stocking two tanks, one for fishes and one for 

 frogs, and had eggs of both to use for that purpose, the first practical 

 question for him would be which are the eggs of fishes and which are 

 the eggs of frogs? 



It is just so in the development of the human mind. As far as 

 the practical results are concerned, the one bit of knowledge, the pos- 

 session of which will best enable us to predict the fully developed 

 adult, is an answer to the same sort of question as that we would first 

 wish to know in the case of the fishes and the frogs. What is the 

 nature of the primary germ-cells? Since for obvious reasons we can 

 not know this nature, the next' best thing to know is its theoretical 

 probabilities as derived from a proper study of the ancestry. 



It would seem from the facts here studied that the probabilities 

 will be roughly as given below. Quality possessed by entire ancestry 

 is almost sure to appear. Quality possessed by one parent and half 

 the ancestry is likely to appear with almost equal force, in one out of 

 every two descendants. Quality possessed by one parent only, and 

 not present in the ancestry, has one chance in about four for its 

 appearance in the progeny. Quality not possessed by either parent, 

 but present in all the grandparents and most of the remaining ancestry, 

 would also have about one chance in two for its appearance in one of 

 the children. If only one of the great grandparents possessed the quality 

 in question, then the chances of its appearance in any one of the 

 grandchildren of this ancestor would be only about one chance in six- 

 teen. It would be, however, very unlikely that some of the remote 

 ancestry had not also the quality in question, so the chances would 

 be raised in a greater or less degree according to the proportionate 

 amount of this remote influence. 



There does not seem to be the least reason for assuming that the 

 male side is any more or less potent than the female side in the 

 transmission of family characteristics, nor does there seem to be any 

 grounds for the fancied belief that sons tend to resemble their mothers 

 and daughters their fathers, or the more generally accepted scientific 

 belief to the contrary. No figures have been compiled on this subject 



