480 



Two volumes are missing. The closing chapter of the seconcl, were 

 it written, would deal with the evolution of organic matter — the 

 step preceding the evolution of living forms. Habitually carrying 

 with me in thought the contents of this unwritten chapter, I have, 

 in some cases, expressed myself as though the reader had it before 

 him ; and have thus rendered some of my statements liable to 

 misconstructions. Apart from this, however, the explanation of the 

 apparent inconsistency is very simple, if not very obvious. In the first 

 place, I do not believe io the " spontaneous generation" commonly 

 alleged, and referred to in the note ; and so httle have 1 associated 

 in thought this alleged ''spontaneous generation" which I dis- 

 believe, with the generation by evolution which I do believe, that the 

 repudiation of the one never occurred to me as liable to be taken for re- 

 pudiation of theother. That cresituTeshsLYmg quite specific sti^uctureseiTe 

 evolved in the course of a few hours, without antecedents calculated 

 to determine their specific forms, is to me incredible. Not only the 

 estabhshed truths of Biology, but the established truths of science 

 in general, negative the supposition that organisms having struc- 

 tures definite enough to identify them as belonging to known genera 

 and species, can be produced in the absence of germs derived from 

 antecedent organisms of the same genera and species. If there can 

 suddenly be imposed on simple protoplasm the organization which 

 constitutes it a Paramoecium^ I see no reason why animals of greater 

 complexity, or indeed of any complexity, may not be constituted 

 after the same manner. In brief, I do not accept these alleged facts 

 as exemplifying Evolution, because they imply something immensely 

 beyond that which Evolution, as I understand it, can achieve. In 

 the second place, my disbehef extends not only to the alleged cases 

 of " spontaneous generation," but to every case akin to them. The 

 very conception of spontaneity is wholly incongruous with the con- 

 ception of Evolution. For this reason I regard as objectionable Mr. 

 Darwin's phrase " spontaneous variation " (as indeed he does himself); 

 and I have sought to show that there are always assignable causes of 

 variation. No form of Evolution, inorganic or organic, can be 

 spontaneous ; but in every instance the antecedent forces must be 

 adequate in their quantities, kinds, and distributions, to work the 

 observed effects. Neither the alleged cases of " spontaneous gene- 

 ration," nor any imaginable cases in the least allied to them, fulfil 

 this requirement. 



If, accepting these alleged cases of " spontaneous generation," I 

 had assumed, as your reviewer seems to do, that the evolution of 

 organic life commenced in an analogous way ; then, indeed, I should 

 have left myself open to a fatal criticism. This supposed '' spon- 

 taneous generation " habitually occurs in menstrua that contain 

 either organic matter, or matter originally derived from organisms ; 

 and such organic matter, proceeding in all known cases from organ- 

 isms of a higher kind, implies the pre-existence of such higher 



