ON BIOLOGY 57 



mated jelly, which they are puzzled to distinguish from 

 those specks which they reached by the animal road." 



This great truth, so clearly stated by Huxley, no doubt 

 likewise expresses what has been the manner of growth 

 and development of plants and animals in the history of 

 the earth. No one who has properly examined the evi- 

 dence can now doubt for a moment that in the beginning 

 of the world the primitive material from which all ani- 

 mals and plants have since arisen was the absolutely 

 organless protoplasm. In other words we may say that 

 the history of the origin, growth and development of all 

 living forms in time is epitomized in the history of the 

 origin, growth and development of existing plants and 

 animals; just as the history of the origin, growth and 

 development of any individual species of animal is an 

 epitome of the history of the origin, growth and develop- 

 ment of the tribe to which that species belongs. 



Passing to physiology, another one of our main divi- 

 sions of biology, we find all that holds true of structure 

 also holds true of the functions of the structures; and, in 

 the higher or more complex types of animals the func- 

 tions performed by the organs are complicated, but as we 

 study them in passing down the series we find they be- 

 come gradually more and more simple in their perform- 

 ance. Even the mental faculties form no exception to 

 this rule, for notwithstanding the marvelous workings of 

 the mind and the brain in the highest types of man, those 

 faculties can be traced down through the animal series 

 until at last we meet with their very rudiments as per- 

 formed by the brains of the lowest forms of animal life. 

 It was the distinguished British biologist, Mr. George J. 

 Romanes, who said in an admirable article published some 

 six or seven years ago in the North American Review: 



"After centuries of intellectual conquest in all regions 

 of the phenomenal universe, man has at last begun to 

 find that he may apply in a new and most unexpected 

 manner the adage of antiquity, 'know thyself.' For he 

 has begun to perceive a strong probability, if not an ac- 

 tual certainty, that his own living nature is identical in 

 kind with the nature of all other life, and that even the 

 most amazing side of that nature nay, the most amazing 

 of all things within the reach of his knowledge, the 

 human mind itself is but the topmost inflorescence of 

 one mighty growth whose roots and stem and many 

 branches are sunk in the abyss of planetary time." 



I have never been in sympathy with those observers 

 who would draw hard and fast lines, the lines of instinct 



