21 6 ESSENTIALS OF BIOLOGY 



example, to develop into a whiting. Thus it is the " internal 

 factors," that is, the potentialities of the organization, that are 

 specific in nature. 



V. It is an intensive manifoldness. 



Although we must think of an organism as being one undivided, 

 whole thing our attention analyses it, both in respect of its 

 morphology and activities, into many parts, structures, organs, 

 modes of functioning and behaviour : at all events these are aspects 

 of the organism. Since the organization, acting on the environ- 

 ment, becomes these parts, or aspects, we may think of the latter 

 as being in the organization — as the potentialities. Our analyses 

 show us the parts, organs, etc., as being extended in space, laid 

 alongside each other, being dorsal or ventral, right and left, 

 anterior or posterior, etc. : in short, being spatially related. 

 But we cannot discern such spatial relationships in the develop- 

 mental potentialities, though it may be convenient to think about 

 the latter as manifold. Therefore the manifoldness is intensive, 

 that is, the '* parts " of the organization interpenetrate each other. 

 The conception has no difficulties, thus the notes of a musical 

 chord, accurately played, are not spatially or temporally separate 

 from each other though experience enables us to analyse the chord 

 so as to distinguish its constituents. 



vi. The developmental organization cannot clearly he thought 

 about as being in space but it acts into space. 



That means that the intensiveness of the organization in the 

 ovum about to develop becomes an extension of parts (blasto- 

 meres, anlagen, organs and tissues) that can be measured and given 

 space-coordinates. It is this discontinuity that perplexes us 

 and makes the conception of a developmental agency obscure. 

 By reason of our application of (classical) physical conceptions 

 (matter, energy, etc.) to the embryogenetic process we try to give 

 every developmental phase that can be drawn, measured and 

 physically described a preceding phase that can also be physically 

 described. Thus there were the historic, crude, preformationist 

 hypotheses and now there is the modern geneticist outlook that 

 makes the genes physical things just as characters, organs and 

 parts resulting from the activities of the genes are physical things. 

 But looking at the problem candidly and critically we simply 

 cannot discover anything that " causes " development in the ovum 

 — that is, anything physically extended. What we know is that 



