160 ON THE INTERNAL FORM AND [ch. 



us as to its electrical manifestations or properties. Matter of 

 itself has no power to do, to make, or to become : it is in energy 

 that all these potentialities reside, energy invisibly associated with 

 the material system, and in interaction with the energies of the 

 surrounding universe. 



That "function presupposes structure" has been declared an 

 accepted axiom of biology. Who it was that so formulated the 

 aphorism I do not know ; but as regards the structure of the cell 

 it harks back to Briicke, with whose demand for a mechanism, 

 or organisation, within the cell histologists have ever since 

 been attempting to comply*. But unless we mean to include 

 thereby invisible, and merely chemical or molecular, structure, 

 we come at once on dangerous ground. For we have seen, in 

 a former chapter, that some minute "organisms" are already 

 known of such all but infinitesimal magnitudes that everything 

 which the morphologist is accustomed to conceive as "structure" 

 has become physically impossible ; and moreover recent research 

 tends generally to reduce, rather than to extend, our conceptions 

 of the visible structure necessarily inherent in living protoplasm. 

 The microscopic structure which, in the last resort or in the simplest 

 cases, it seems to shew, is that of a more or less viscous colloid, 

 or rather mixture of colloids, and nothing more. Now, as Clerk 

 Maxwell puts it, in discussing this very problem, "one material 

 system can differ from another only in the configuration and 

 motion which it has at a given instant t-" If we cannot assume 

 differences in structure, we must assume differences in niotion, that 

 is to say, in energy. And if we cannot do this, then indeed we are 

 thrown back upon modes of reasoning unauthorised in physical 

 science, and shall find ourselves constrained to assume, or to 

 "admit, that the properties of a germ are not those of a purely 

 material system." 



* "Wir miissen deshalb den lebenden Zellen, abgesehen von der Molekular- 

 structur der organischen Verbindungen welche sie enthalt, noch eine andere und 

 in anderer Weise complicirte Structur zuschreiben, und diese es ist welche wir 

 mit dem Namen Organisation bezeiclmen," Briicke^ Die Elementarorganismen, 

 Wiener Sitzungsber. xliv, 1861, p. 386; quoted by Wilson, The Cell, etc. p. 289. 

 Cf. also Hardy, Journ. of Physiol, xxiv, 1899, p. 159. 



f Precisely as in the Lucretian concursus, motus, ordo, positura,figurae, whereby 

 bodies miitato ordine mutant naturam. 



