666 Studies in the Theory of Descent. 



heredity, is up to the present time wanting. That 

 he has not done so proves on the one hand that 

 he despised the dialectical art, but, on the other 

 hand, that he himself has not overlooked the sub- 

 serviency of the total phenomenon to law, and 

 that he grants the possibility of finding a me- 

 chanical explanation therefor. If, in fact, the 

 power of inheritance does not depend upon 

 mechanical principles, I know not what organic 

 processes we are entitled to'regard as mechanical, 

 since they are all dependent in essence upon 

 heredity, with which process they are at one, and 

 from which they cannot be thought of as isolated. 

 Haeckel correctly designates reproduction as sur- 

 plus individual growth, and accordingly refers the 

 phenomena of heredity to those of growth. Con- 

 versely, growth may also be designated reproduc- 

 tion, since it depends upon a continuous process 

 of multiplication of the cells composing the 

 organism, from the germ-cell to the innumerable 

 congeries of variously differentiated cells of the 

 highly developed animal body. Who can fail to 

 see that these two processes, the reproduction of 

 the germ-cell and its offspring in the economy of 

 the individual, and the reproduction of individuals 

 and species in the economy of the organic world, 

 show an exact and by no means simply super- 

 ficial analogy ? 10 But whoso grants this must 

 also conceive both processes to depend upon the 

 10 See Haeckel's " Generelle Morphologic," ii. 107. 



