XII] OF THE FORAMINIFEHA 611 



adaptation to an environment, of higher and lower, of "better" 

 and "worse." This is the fundamental difference between the 

 " ex;planations " of the physicist and those of the biologist. 



In the order of physical and mathematical complexity there is 

 no question of the sequence of historic time. The forces that 

 bring about the sphere, the cylinder or the elhpsoid are the same 

 yesterday and to-morrow. A snow-crystal is the same to-day as 

 when the first snows fell. The physical forces which mould the 

 forms of Orbuhna, of Astrorhiza, of Lagena or of Nodosaria to-day 

 were still the same, and for aught we have reason to beheve the 

 physical conditions under which they worked were not appreciably 

 different, in that yesterday which we call the Cretaceous epoch; 

 or, for aught we know, throughout all that duration of time which 

 is marked, but not measured, by the geological record. 



In a word, the minuteness of our organism brings its conforma- 

 tion as a whole within the range of the molecular forces; the 

 laws of its growth and form appear to he on simple lines ; what 

 Bergson calls* the "ideal kinship" is plain and certain, but the 

 "material affihation" is problematic and obscure; and, in the 

 end and upshot, it seems to me by no means certain that the 

 biologist's usual mode of reasoning is appropriate to the case, or 

 that the concept of continuous historical evolution must necessarily, 

 or may safely and legitimately, be employed. 



* The evolutionist theory, as Bergson puts it, "consists above all in establishing 

 relations of ideal kinship, and in maintaining that wherever there is this relation of, 

 so to speak, logical affiliation between forms, there is also a relation of chronological 

 succession between the species in which these forms are materialised'" : Creative 

 Evolution, 1911, p. 26. Cf. supra, p. 251. 



39—2 



