298 



SCIENCE 



[N. S. Vol. XXXVI. No. 923 



would be equally impossible for the geolo- 

 gist to trace its beginnings, and were it 

 still becoming evolved in the same situa- 

 tions, it would be almost as impossible for 

 the microscopist to follow its evolution. 

 We are therefore not likely to obtain direct 

 evidence regarding such a transformation 

 ef non-living into living matter in nature, 

 even if it is occurring under our eyes. 



An obvious objection to the idea that the 

 production of living matter from non- 

 living has happened more than once is that, 

 had this been the case, the geological record 

 should reveal more than one paleontologieal 

 series. This objection assumes that evolu- 

 tion would in every ease take an exactly 

 similar course and proceed to the same goal 

 — an assumption which is, to say the least, 

 improbable. If, as might well be the case, 

 in any other paleontologieal series than the 

 one with which we are acquainted the proc- 

 ess of evolution of living beings did not 

 proceed beyond protista, there would be no 

 obvious geological evidence regarding it; 

 such evidence would only be discoverable 

 by a carefully directed search made with 

 that particular object in view. I would 

 not by any means minimize the difficulties 

 which attend the suggestion that the evolu- 

 tion of life may have occurred more than 

 once or may still be happening, but on the 

 other hand, it must not be ignored that 

 those which attend the assumption that the 

 production of life has occurred once only 

 are equallj^ serious. Indeed, had the idea 

 of the possibility of a multiple evolution of 

 living substance been first in the field, I 

 doubt if the prevalent belief regarding a 

 single fortuitous production of life upon 

 the globe would have become established 

 among biologists — so much are we liable to 

 be influenced by the impressions we receive 

 in scientific childhood! 



Assuming the evolution of living matter 

 to have occurred — whether once only or 



more frequently matters not for the mo- 

 ment — and in the form suggested, viz., as a 

 mass of colloidal slime possessing the prop- 

 erty of assimilation and therefore of 

 growth, reproduction would follow as a 

 matter of course. For all material of this 

 physical nature — fluid or semi-fluid in 

 character — has a tendency to undergo sub- 

 division when its bulk exceeds a certain 

 size. The subdivision may be into equal or 

 nearly equal parts, or it may take the form 

 of buds. In either case every separated 

 part would resemble the parent in chemical 

 and physical properties, and Avould equally 

 possess the property of taking in and 

 assimilating suitable material from its 

 liquid environment, growing in bulk and 

 reproducing its like by subdivision. Omne 

 vivum e vivo. In this way from any begin- 

 ning of living material a primitive form of 

 life would spread, and would gradually 

 people the globe. The establishment of life 

 being once effected, all forms of organiza- 

 tion follow under the inevitable laws of 

 evolution. Ce n'est que le premier pas qui 

 coute. 



We can trace in imagination the segre- 

 gation of a more highly phosphorized por- 

 tion of the primitive living matter, which 

 we may now consider to have become more 

 akin to the protoplasm of organisms with 

 which Ave are familiar. This more phos- 

 phorized portion might not for myriads of 

 generations take the form of a definite 

 niicleus, but it would be composed of mate- 

 rial having a composition and qualities 

 similar to those of the nucleus of a cell. 

 Prominent among these qualities is that of 

 catalysis — the function of effecting pro- 

 found chemical changes in other material 

 in contact with it without itself undergoing 

 permanent change. This catalytic function 

 may have been exercised directly by the 

 living substance or may have been carried 

 on through the agency of the enzymes 



