JoLY — The Abundance of Life. 87 



in course of time, to the species in its modified form : for although 

 the train of events in the first case proceeded downwards from the 

 high to the low organism, there is seemingly no correlation of 

 events involved which we might not expect to be reversible in 

 order of occurrence. The birth and growth of the individual 

 finds, of course, its parallel in this simile, in the supposed repe- 

 tition of evolution. But in the case of the time-limits of the 

 individual we have a more complex predestination to account 

 for; not only the life-history of each cell but a different life- 

 history for succeeding cells ; for if we do not suppose changes in 

 the life-history of the succeeding generations of cells, why and how 

 is the power of metabolism ultimately lost ? 



I confess that only in the vague conception of a harmonizing 

 or formative force derived from the germ, perishing in each cell 

 from internal causes, but handed from cell to cell till the formative 

 force itself degrades into molecular discords, can I form any 

 physical representation of the successive events of life. The degra- 

 dation of the molecular formative force might be supposed involved 

 in its frequent transference according to some such actions as occur 

 in inanimate nature. Thus, ultimately, to the waste within the 

 cell, to the presence of a force retardative of its perpetual harmonic 

 motions, the death of the individual is to be ascribed. Perhaps in 

 protoplasmic waste the existence of a universal death should be 

 recognised. It is here we seem to touch inanimate nature ; and 

 we are led back to a former conclusion that the organism in its 

 unconstrained state is to be regarded as a " contrivance " for 

 evading the dynamic tendencies of actions in which matter par- 

 ticipates.^ 



1 In connexion with, tlie predestinating power and possible complexity of the germ, 

 it is instructiye to reflect on the veiy great molecular population of even the smallest 

 spores — giving rise to very simple forms. Thus, the spores of the unicellular Schizo- 

 mycetes are estimated to dimensions as low as 1/10,000 of a millimetre in diameter 

 (Cornil et Bates, "Les Eacteries," i. 37). From Sir William Thomson's estimate of 

 the nrunher of molecules in water, comprised within the length of a wave-length of 

 yellow light ("The Size of Atoms," Proc. R. I., vol. x., p. 185), it is probable that 

 the spoi-es contain some 500,000 molecules, while one hundred molecules range along 

 a diameter. 



Dr. Johnstone Stoney, in a lecture delivered before the Eoyal Dublin Society some 

 years ago, suggested similar reflections. 



