life: its nature, origin, and maintenance SCHAFER. 507 



evidence regarding such a transformation of nonliving into living 

 matter in nature, even if it is occurring under our eyes. 



An obvious objection to tlie idea that the production of Uving 

 matter from nonhving has happened more than once is that, had this 

 been the case, the geological record should reveal more than one 

 paleontological series. This objection assumes that evolution would 

 in every case 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 paleontological series than the 

 one with which we are acquainted, the process of evolution of living 

 beings did not proceed beyond Protista, there would be no obvious 

 geological evidence regarding it; such evidence would only be dis- 

 coverable 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 evolution of hfe 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 hfe has occurred once only, are equally serious. 

 Indeed, hatl the idea of the possibility of a multiple evolution of 

 living substance been first in the field, I doubt if the prevalent 

 behef regarding a single fortuitous production of life upon the globe 

 would have become estabhshed among biologists — so much are we 

 liable to be influenced by the impressions we receive in scientific 

 childhood. 



FURTHER COURSE OF EVOLUTION OF LIFE. 



Assuming the evolution of livmg matter to have occurred — whether 

 once only or more frequently matters not for the moment — and in the 

 form suggested, viz, as a mass of colloidal slime possessing the property 

 of assimilation and therefore of growth, reproduction would foUow as 

 a matter of course, for all material of this physical nature — fluid or 

 semifluid in character — has a tendency to undergo subdivision when 

 its bulk exceeds a certain size. The subtlivision may be mto 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 would equally possess the property of taking 

 in and assimilating suitable material from its liquid environment, 

 growing in bulk, and reproducing its hke by subdivision. Omne 

 vivum e vivo. In this way from any beginning of living material a 



1 Lankestor (Art. " Protozoa," Encycl. Brit., tenth edition) conceives that the first protoplasm fed on the 

 antecedent steps in its own evolution. F. J. Allen (JJrit. A.ssoc. Reports, ISOG), comes to tho conclusion 

 that living substance is probably constantly being produced, but that tliis fails to make itself evident owing 

 to tho substance being seized and assimilated by existing organisms. IIo believes that "in accounting 

 for the flrst origin of life on this earth it is not necessary that, as PQiiger assum-d, tho planet should have 

 been at a former period a glowing fireball." He "prefers to believe that the circumstances which support 

 life would also favor its origin." And elsewhere: " Life is not an extraordinary phenomenon, not even an 

 importation from sumo other sphere, but rather tho actual outcome of circumstances ou this earth." 



