76 BROOKS— HEREDITY AND VARIATION. [April 20. 



neither exists in the organism nor in the environment, because it is 

 in the reciprocal interaction between the two. The biological types 

 of w^hich the biometricians tell us are neither 'external standards to 

 which living beings approach and from which they recede by varia- 

 tion, nor are they standards fixed in living beings by heredity. 

 Inheritance and variation are not two things, but two imperfect 

 views of a single process, for the difference between them is neither 

 in living beings nor in any external standard of extermination, but 

 in the reciprocal interaction between each living being and its com- 

 petitors and enemies and sources of food and the others conditions 

 of life. 



If the being of the individual organism is not in itself, but in 

 the reciprocal interaction between it and its environment, and if the 

 being of species is not in germ cells but in the reciprocal interaction 

 between living beings and their environment, then the being of the 

 canine species is of the same sort as the being of a dog, and that of 

 everything else in nature. 



• Is it as a self-sufficient thing in itself, or as part of the universe, 

 that the stone exhibits gravitation? "When Sir Isaac Newton 

 made his speech about the child and the pebble : " Did he mean," 

 asks Dr. Holmes, " to speak slightingly of a pebble? A body which 

 knows all the currents of force that traverse the globe ; which holds 

 fast by invisible threads to the ring of Saturn and the belt of Orion." 

 " This is certain," says Locke, " things however absolute and entire 

 they seem in themselves, are but retainers to other parts of nature, 

 for that which they are most taken notice of by us. Their ob- 

 servable qualities, actions, and powers, are owing to something with- 

 out them ; and there is not so complete and perfect a part that we 

 know of nature, which does not owe the being it has, and the ex- 

 cellencies of it, to its neighbours ; and we must not confine our 

 thoughts within the surface of any body, but look a great deal 

 farther, to comprehend perfectly those qualities that are in it." 



Since these things are true, is it not time to have done, once for 

 all, with the metaphysical, pre-Darwinian notion of species, as 

 something that resides in germ cells and is handed down by a 

 substance of hereditv? 



