1889.] NEW-YORK MICROSCOPICAL SOCIETY. ^ 23 



iar, Mr. Spencer appears to be the only one, however, who has 

 plainly avoided the application to the problem of experimental 

 tests, and has escaped the inferences therefrom, by pleading 

 that at this juncture a factor of infinity is introduced : — that 

 the transitions one would seek to trace are so " insensible " that 

 endings and beginnings have no existence. Meanwhile the in- 

 vestigations of bacteriologists are piling higher and higher the 

 proof of the old doctrine, " omne vivutn ex vivo," and making it 

 more and more certain that there is no confusion of genetic lines 

 amongst even the " lowest " living forms. 



And here I must leave the subject, lame and impotent though 

 the conclusion may be. I have not undertaken the discussion 

 of this topic in any spirit of captiousness, nor with any preju- 

 dice against the evolution theory. In the domain in which 

 Mr. Darwin worked I look upon Natural Selection as a well- 

 established principle. In the developmental idea as extended 

 and expounded by Herbert Spencer I find much that appeals 

 strongly to my sense of fitness and consistency and, if possible, 

 I could see the hypothesis become a proven law of nature with- 

 out a shock to my mental or moral status. I have no fear of 

 anything that is true. 



But what I have endeavored to show is ; 



1. That a transition from not-living matter to living forms is 

 an essential step in the process of evolution. 



2. That at the point at which experimental proof is applica- 

 ble (namely, to present and continual archebiosis) the theory 

 of such a transition is discredited, if not disproved. 



3. That scientists generally accept this conclusion, and that 

 those who are thorough evolutionists are confined to the 

 mere belief that the step from the not-living to the living 

 was taken at some remotely early period, beyond the reach of 

 evidence. 



And, finally, I submit, as a consequence of these premises, 

 that the General Theory of Evolution is still in the stage of 

 hypothesis, and that in the gap between lifeless substances and 

 living forms we have the veritable ^^ Missi?tg Link." 



