DARWINISM. 19 



parent. As, for instance, the child of a gouty father, 

 though it may be destined in old age to inherit the 

 disease, is not born with the gout, any more than a 

 calf is born with horns, or a cherry-tree produced 

 covered with cherries. In the life of every creature 

 there is not merely growth, but development. At 

 every stage of life it is possible for some quality ac- 

 quired by variation to be fixed by Natural Selection. 

 But in the embryonic and earliest stages of develop- 

 ment, variation is least likely to be of service to any 

 creature. Such variations, therefore, will less often be 

 selected than others, and if it be true that many species 

 have a common ancestry, then it ought to be found that 

 in their embryonic and earliest stages they resemble one 

 another. This is precisely what we do find. Plants, 

 the most remote in appearance and properties when 

 full grown, differ but slightly in their cotyledons: the 

 difference between the egg of a nightingale and the egg 

 of an ostrich bears no proportion to the dissimilarity 

 between the two birds when fully developed; nor by 

 comparing the roe of a herring with the roe of a salmon 

 could you possibly guess, before experience, how the 

 full-grown fish would differ. But in the life of every 

 human being there is a stage of development, at which 

 the most sagacious physician could not distinguish him 

 from the embryo of a snake, a lizard, a bird, or an ape 1 . 



1 An important caution may here be quoted from Mr. Herbert 

 Spencer. ' An impression,' he says, ' has been given by those who have 

 popularized the sentiments of Embryologists, that, during its develop- 

 ment, each higher organism passes through stages in which it resembles 

 the adult forms of lower organisms that the embryo of a man is at oife 



c a 



