1 54 E VOL UTION, OLD AND NE W. 



entirety, from first to last, and then reflect upon the 

 manner in which these two substances the living 

 and the inanimate act and react upon one another, 

 would see that every living being is a mould which 

 casts into its own shape those substances upon which it 

 feeds ; that it is this assimilation which constitutes the 

 growth of the body, whose development is not simply 

 an augmentation of volume, but an extension in all its 

 dimensions, a penetration of new matter into all parts 

 of its mass: he would see that these parts augment 

 proportionately with the whole, and the whole pro- 

 portionately with these parts, while general configura- 

 tion remains the same until the full development 

 is accomplished. . . . He would see that man, the 

 quadruped, the cetacean, the bird, reptile, insect, tree, 

 plant, herb, all are nourished, grow, and reproduce 

 themselves on this same system, and that though their 

 manner of feeding and of reproducing themselves may 

 appear so different, this is only because the general 

 and common cause upon which these operations depend 

 can only operate in the individual agreeably with 

 the form of each species. Travelling onward (for it 

 has taken the human mind ages to arrive at these great 

 truths, from which all others are derived), he would 

 compare living forms, give them names to distinguish 

 them, and other names to connect them with each 

 other. Taking his own body as the model with which 

 all living forms should be compared, and having 

 measured them, explained them thoroughly, and com- 

 pared them in all their parts, he would see that there 

 is but small difference between the forms of living 

 beings ; that by dissecting the ape he could arrive at 



