INSTINCT, REASON, ETC. 69 



be in accord with the fourth and last class of thinkers as re- 

 gards our present subject. These are they who believe that one 

 vital germ settled on this earth, and from that all the various 

 classes of plants and animals gradually evolved by natural 

 selection, man included. Mind you, not that man descended 

 from a monkey, as ignorant people charge Darwin with 

 postulating — for he is the leader of this school of thought — 

 but that man, monkeys, fish, plants, and all created beings 

 which have possessed the vital spark, have gradually been 

 evolved from the same original germ. 



This is the line of thought I take up in my paper of this 

 evening, and I purpose trying to collate and serve up to you 

 in a condensed form thoughts that have tossed about in my 

 brain for years in a disorderly sort of way. Perchance I may 

 be fortunate enough to put the subject in a different light 

 from that in which you have been accustomed to view it, 

 though I cannot hope there will be much originality in my 

 remarks. 



It is a law of physiology, which, I think, none will 

 dispute, that " function begets structure," and conversely that 

 " structure determines function." They act and re-act one on 

 the other ; therefore, it is a certainty that when we examine, 

 let us say the fin of a fish, the wing of a fowl, the leg and paw 

 of a cat, the arm and hand of a monkey or a man, we know 

 that in exactly the same ratio as they differ in structure and 

 complexity, so will the acts they perform differ in number 

 and complexity. So with the brain and the nervous system. 

 In proportion as the higher nerve centres are developed in 

 structure, so will the functions they determine be developed 

 in structure. 



Thus, at each end of a long series of structural and 

 functional changes we find creatures so different, that, had we 

 not proof of their relationship by knowing the various forms 

 that go to make up the links in the chain, we should at once 

 say, as did the naturalists of a former age, " these creatures 

 cannot be related," and we should fall back on special acts of 

 creation to account for them; and if we were at the time 

 discussing the mental faculties, we should as certainly draw a 

 hard and fast line between Reason and Instinct, and Instinct 

 and Reflex Action, and pronounce their differences as being 

 those of kind and not merely of degree. 



Now, the school of thinkers to which I profess as a very 

 humble follower to belong, maintain that these apparent 

 differences in kind, nay real differences in kind now, that we 

 see amongst created beings are produced from an accumula- 



