7 i8 THE POPULAR SCIENCE MONTHLY. 



is the whole notion of life having been originally " breathed " into 

 one or more organic forms. Mr. Spencer's language is happily free 

 from both these defects : he neither uses the phraseology of the Crea- 

 tive hypothesis, nor does he adopt a definition of biological " indi- 

 viduality," at variance with the Evolution philosophy. He distinctly 

 teaches that living matter must have been at first formless, and that 

 multiplication would have taken place, as among the lowest forms of 

 the present day, exclusively by agamic methods — nay, more, he 

 teaches that living matter must have been the gradual product or 

 outcome of antecedent material combinations. " Construed in terms 

 of evolution," he says, 1 " every kind of being is conceived as a prod- 

 uct of modifications wrought by insensible gradations on a pre- 

 existing kind of being, and this holds fully of the supposed £ com- 

 mencements of organic life,' as of all subsequent developments of 

 organic life." But on the question whether the process of Archebiosis 

 (life-evolution) is likely to have occurred once only, as Mr. Darwin 

 seems to hint, or in multitudinous centres scattered over the earth's 

 surface, Mr. Spencer makes no definite statement. The latter belief 

 would, however, be entirely in accordance with his general doctrine ; 

 and we seem all the more entitled to infer that Mr. Spencer inclines 

 to the notion of a multiple occurrence of Archebiosis, both in space 

 and in time, since he does not reject the possibility of its occurrence 

 in our own day. Granting " that the formation of organic matter and 

 the evolution of life in its lowest forms may go on under existing 

 cosmical conditions," he believes it " more likely that the formation 

 of such matter and of such forms took place at a time when the heat 

 of the earth's surface was falling through those ranges of temperature 

 at which the higher organic compounds are unstable." But conclusions 

 which we are only able to infer from the writings of Mr. Spencer 

 have been distinctly enunciated by Mr. G. H. Lewes. In a criticism 

 of the " Darwinian Hypothesis," he very forcibly pointed out that it 

 is quite compatible with the hypothesis of evolution to admit a va- 

 riety of starting-points for the formation of living matter, and he con- 

 sequently laid down in principle a very important extension of the 

 Darwinian doctrine, in its application to higher organisms. He 

 says : 2 " Although observation reveals that the bond of kinship does 

 really unite many divergent forms, and the principle of Descent with 

 Natural Selection will account for many of the resemblances and dif- 

 ferences, there is at present no warrant for assuming that all resem- 

 blances and differences are due to this one cause, but, on the contrary, 

 we are justified in assuming a deeper principle which may be thus 

 formulated : All the complex organisms are evolved from organisms 

 less complex, as these were evolved from simpler forms : the link 

 which unites all organisms is not always the common bond of heri- 

 tage, but the uniformity of organic laws acting under uniform condi- 

 1 " Principles of Biology," vol. ii., Appendix, p. 482. 2 Fortnightly Review, 1868. 



