3i8 PLEASANT WAYS IN SCIENCE. 



theory arise from this unnecessary and not logically sound 

 doctrine. I pointed out, rather more than three years ago, 

 in an article " On some of our Blood Relations," in a weekly 

 scientific journal, that the analogy between the descent of 

 races and the descent of individual members of any race, 

 requires us rather to believe that the remote progenitor of 

 the human race and the Simiadse has had its share though 

 a less share in the generation of other races related to these 

 in more or less remote degrees. I may perhaps most con- 

 veniently present the considerations on which I based this 

 conclusion, by means of a somewhat familiar illustration : 



Let us take two persons, brother and sister (whom let 

 us call the pair A), as analogues of the human race. Then 

 these two have four great-grandparents on the father's side, 

 and four on the mother's side. All these may be regarded 

 as equally related to the pair A. Now, let us suppose that 

 the descendants of the four families of great-grandparents 

 intermarry, no marriages being in any case made outside 

 these families, and that the descendants in the same gene- 

 ration as the pair A are regarded as corresponding to the 

 entire order of the Simiadse, the pair A representing, as 

 already agreed, the race of man, and all families outside the 

 descendants of the four great-grandparental families corre- 

 sponding to orders of animals more distantly related than 

 the Simiadae to man. Then we have what corresponds (so 

 far as our illustration is concerned) to Darwin's views re- 

 specting man and the Simiadae, and animals lower in the 

 scale of life. The first cousins of the pair A may be taken 

 as representing the anthropoid apes ; the second cousins as 

 representing the lemurs or half-apes; the third cousins as 

 representing the platyrhine or American apes. The entire 

 family including the pair A, representing man is descended 

 also, in accordance with the Darwinian view, from a single 

 family of progenitors, no outside families sharing descent, 

 though all share blood, with that family. 



But manifestly, this is an entirely artificial and improbable 

 arrangement in the case of families. The eight grand 



