78 THE BEGINNINGS OF LIFE. 



pounds fall more or less immediately into such and 

 such living combinations J . The influence of the pre- 

 existing protoplasm would seem to expend itself chiefly 

 in the building up of living matter after its own like- 

 ness. This, however, is a property possessed by crystals 

 as well as organisms, and, as Mr. Lewes pointed out, 

 such a resemblance has been alluded to by earlier 

 writers. Mr. Lewes says 2 : c The nourishment of 

 various organs from a common fluid, each selecting 

 from that fluid only those molecules that are like itself, 

 rejecting all the rest, is very similar to the formation 

 of various crystals in a solution of different salts, each 

 salt separating from the solution only those molecules 

 that are like itself. Reil long ago called attention to 



1 Here, at all events, the facts would not seem to show that there 

 is any extraordinary difficulty to be overcome in order that matter may 

 fall into ' vital ' modes of combination. And the absolute necessity for 

 long intervals of time during which numerous intermediate stages may 

 be passed through, seems from this alone to be rendered somewhat 

 improbable, even had we not an abundance of experimental evidence 

 to bring forward in opposition to this mere theoretical supposition. 

 We may perhaps derive some valuable hints as to the facility with 

 which protoplasm and chlorophyll make their appearance, by reference 

 to the changes which take place in the seed-cells of CEdogonium, Palmo- 

 glaa, and other algae (see vol. i. p. 1 78). In the midst of the living tissue, 

 fat and starch globules are gradually formed, till it seems to be almost 

 totally converted into these products which are ordinarily deemed life- 

 less. But, after a time, and under the genial influence of heat, light 

 and moisture, a molecular re-arrangement in the inverse order begins 

 to take place. The needful elements are all there ; the old combinations 

 are disturbed, new combinations" arise, and again there slowly appears 

 the chlorophyll-containing, living plotoplasm. 



2 Loc. cit., p. 619 



