THE PROBLEMS ILLUSTRATED 17 



the germ- cells had to be elucidated, the general idea of evolu- 

 tion had to be realised, before the problems of heredity and 

 inheritance could even be stated with precision. Moreover, 

 it seems to have required the experience of many years of 

 "fumbling" before the main body of biologists became con- 

 vinced that the problems could not be satisfactorily studied 

 in the armchair, nor settled by a priori argument. Now, however, 

 it is unanimously agreed that a satisfactory study of heredity 

 and inheritance demands a minute inquiry into the history of the 

 germ-cells, a statistical study of the characters of successive 

 generations, a careful criticism of the older data and of popular 

 impressions, and a testing of hypotheses by experimental 

 breeding. Let us give a few random illustrations in order 

 to show what some of the problems are : 



The race-horse Eclipse was the sire of many foals : it is a 

 problem in heredity to compare them with him, and to inquire 

 into the vital arrangements, in virtue of which many of them 

 reproduced his remarkable quality of swiftness. He had also 

 a peculiar, quite useless spot of colour, which reappeared even 

 in the sixth generation of his progeny. 



In the ancestry of Kaiser Wilhelm II. there have been four 

 grandparents, eight great-grandparents, fourteen (not 16) great- 

 great-grandparents, twenty-four (not 32) great-great-great-grand- 

 parents : it is a problem in heredity to compare the qualities of 

 these successive generations of ancestors, and to inquire if they 

 render more intelligible the illustrious personality whose doings 

 and sayings are familiar to us all. 



The assassin of the Empress of Austria is said to have been 

 the child of a dissolute mother and a dipsomaniac father : it 

 is a problem in heredity to inquire whether this parentage 

 may render more intelligible an outrage which made Europe 

 shudder. 



A white man of considerable intellectual ability marries a 

 negro woman of great physical beauty and strength ; the result 



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