52 INTRODUCTION TO CYTOLOGY 



can receive scientific explanation (i.e., be fitted into an orderly scheme 

 of antecedents and consequents), if at all, only on the basis of the 

 constitution and properties of the materials composing protoplasm; the 

 structural organization of protoplasm; the relation of the reactions and 

 n-sponses of protoplasm in the form of organized units or cells to the 

 environmental conditions; the chain of energy changes occurring in 

 connection with all of the organism's activities; and the correlation of 

 all these conditions and events. It is largely the effort to account for 

 organization and regulatory correlation, and the consequent behavior of 

 the complex organism as a versatile and consistent unit or individual — as 

 something more than a cell aggregate — that has led to certain present 

 day vitalistic theories, as opposed to those which would hold life to be 

 dependent upon "nothing but' : the correlated physico-chemical reac- 

 tions and interactions occurring in protoplasm. 



Whatever our ultimate judgment in this matter shall be — for any 

 decision at present is premature — it is scarcely to be denied that the 

 hypotheses that have thus far been most stimulating to research in 

 biological science and most valuable in analysing the data afforded by 

 this research are those which seek to formulate vital activity in terms of 

 what the physicist for convenience calls matter and energy; and which 

 hold life to be not the manifestation of a super-organic, non-perceptual 

 entity, or even of a distinct perceptual but hypothetical vital energy, 

 but rather the resultant of the many correlated interactions involving 

 only energies of known kinds. The way must not be closed, however, 

 against possible new categories of energy. The description (reduction 

 to order) of our perceptual experience of organic nature, which is the 

 primary task of biological science and which has been scarcely more than 

 begun, must for the present be made as far as possible in terms applicable 

 also to inorganic nature. It is here that achieved results would seem to 

 justify the judicious use of a "mechanistic" working hypothesis, whereby 

 the attempt is made to "describe the changes in organic phenomena by 

 the same conceptual shorthand of notation as suffices to describe inor- 

 ganic phenomena ' ! (Pearson). To what extent our ultimate biological 

 theory is to show the need of non-mechanical energies or principles will 

 depend very largely upon what this scientific description (orderly formu- 

 lation) turns out to be like as investigation proceeds, and also upon the 

 degree of success with which the physicist will resume the phenomena of 

 inorganic nature in mechanical formulae. Thus, as Professor D'Arcy W. 

 Thompson forcefully says : 



"While we keep an open mind on this question of vitalism, or while we lean, 

 as so many of us now do, or even cling with a great yearning, to the belief that 

 something other than the physicalforces animates the dust of which we are made, 

 it is rather the business of the philosopher than of the biologist, or of the biologist 

 only when he has served his humble and severe apprenticeship to philosophy, 



