LIFE OX THE EARTH. 135 



of it. And it would not be too much to affirm, were 

 such vague affirmation worth having, that not one- 

 hundredth part of the animal creation, counted by 

 species, has relation, direct or indirect, to his existence 

 on earth. 



While discarding, however, any such assumption of 

 the dependent relation of other animals to man, we must 

 admit that another relation presses more cogently upon 

 us if we adopt the doctrine of progress in the forms of 

 life by gradual evolution instead of by special creation. 

 This doctrine cannot be held, as it is held by many, 

 without including man as a unit in the scale of pro- 

 gression the highest product of those laws or acci- 

 dents of development by which inferior forms of being 

 are raised to those of higher grade. We cannot stop 

 short at the human threshold, if the argument for 

 transmutation has carried us thus far. But this ques- 

 tion, perfectly justifiable in itself, is one requiring 

 separate discussion, though so closely allied to all 

 other problems of the living world that none can be 

 wholly dissevered from it. 



From the comparative anatomy and physiology of 

 the present day we derive a very exact knowledge of 

 the structural and functional relations of man and 

 other animals, traced upwards from the dawning of 

 life in each. The enquiry rises in interest as we come 

 to the higher orders of mammalia and those quadru- 

 inanous animals the proximity of which to man even 

 nomenclature has been led to recognise. It is needless 

 to cite the several resemblances of structure, and of 

 the functions to which they serve, through all the 



