May 27, 1898.] 



SCIENCE. 



723 



while a mass of matter remains in a state 

 of rest or of uniform direction of motion, 

 except as compelled by some outward force 

 to change that state. 



It may be objected, here, that this differ- 

 ence is a subjective one, and has no objec- 

 tive reality, in that a body, of which the 

 substance is undergoing change, cannot be 

 regarded as strictly the same body after as 

 before the change. 



If the objection be valid we must still 

 remember that it is such a changing phys- 

 ical body which grows, inherits, acquires 

 characters, etc., that we are studying. 



But whether the objection be valid or 

 not, it is essential to keep our attention on 

 the objective reality, the living organism, 

 whatever difiSculties we may have sub- 

 jectively ; and the one group of phenomena 

 which the live organism exhibits character- 

 istically is that of becoming different. 



It is, then, this distinguishing character- 

 istic of the living body — its becoming dif- 

 ferent — that constitutes the point of view 

 from which it is believed the true relations 

 of the organism to other physical bodies 

 may be seen. 



Most biologists, I suppose, are accustomed 

 to treat of living organisms as if they Avere 

 simple physical masses of matter exhibiting 

 their peculiar phenomena solely on account 

 of their peculiar organization, including 

 under that term molecular arrangement of 

 the protoplasm as well as molar organiza- 

 tion of the body of the individual. This 

 conception involves the hypothesis that the 

 peculiarity of the phenomena is to be ac- 

 counted for by difference in kind, state, 

 condition or structure of the component 

 matter of the body. 



Starting with such a conception, let us 

 examine the phenomena and discover of 

 what they consist. 



CLASSIFICATION" OF VITAL PHENOMENA. 



In order to distinguish the phenomena 



of the organism from other phenomena 

 and to restrict our attention, let us call the 

 peculiar visible phenomena of an organism 

 vital phenomena. 



Vital Phenomena may be divided into 

 three groups, according to the relation they 

 bear to mode of existence. 



A. When the question is : Wliat organisms 

 are f the phenomena described in the an- 

 swer are found in the sciences of Botany, 

 Zoology, Anatomy, etc. 



B. When we ask : What do organisms do f 

 the phenomena are described under the 

 names of Physiology, Physiological Chem- 

 istry and Psychophysics. 



C. When we ask : AYhat do organisms be- 

 come f the replies are found in Paleontol- 

 ogy, Embryology, Evolution and Psy- 

 chology. 



This third group (C) of phenomena, be- 

 cause they are modes of becoming different 

 and in a peculiar sense arise or are gen- 

 erated, may be called genetic phenomena. 



The other two classes (A and B) may be 

 left out of discussion for the present, be- 

 cause their relationships to ordinary physical 

 phenomena are sufficiently distinct and 

 evident. 



The Genetic Phenomena of organisms are 

 of, at least, three kinds ; they are de- 

 scribed under the scientific categories of 

 C^ Metabolism, 

 C Development, 

 and Q? Evolution. 



In the phenomena of each of these three 

 categories there are two elements, viz.: (1) 

 a something which preserves its identity 

 and integrity during the phenomena, which 

 may be designated by the symbol x ; and 

 (2) a something which arises during the 

 phenomenon and remains as an increment 

 to the first ; this may be represented by y, 



C\ In Metabolism x stands for the matter 

 flowing into the organism from without, 

 and constitutes the physical basis of the or- 

 ganic body at any particular moment of its 



