38 THE RIDDLE OF THE UNIVERSE. 



ganglionic cells build up the marvellous structure of 

 our brain ; the same four-chambered heart is the 

 central pulsometer in our circulation ; the same 

 thirty-two teeth are set in the same order in our 

 jaws ; the same salivary, hepatic, and gastric glands 

 compass our digestive process ; the same reproductive 

 organs ensure the maintenance of our race. 



It is true that we find, on close examination, certain 

 minor differences in point of size and shape in most 

 of the organs of man and the ape ; but we discover 

 the same, or similar, differences between the higher 

 and lower races of men, when we make a careful com- 

 parison — even, in fact, in a minute comparison of the 

 various individuals of our own race. We find no two 

 persons who have exactly the same size and form of 

 nose, ears, eyes, and so forth. One has only to 

 compare attentively these special features in many 

 different persons in any large company to convince 

 one's self of the astonishing diversity of their con- 

 struction and the infinite variability of specific forms. 

 Not infrequently even two sisters are so much unlike 

 as to make their origin from the same parents almost 

 incredible. Yet all these individual variations do not 

 weaken the significance of the fundamental similarity 

 of structure ; they are traceable to certain minute 

 differences in the growth of the individual features. 



