93 PARTICULAR CONSIDERATIONS ON THE 



am idst a system of things generally stable and at resf Ar# 

 there, then, any such remna its to be traced in our om. 

 day, or during man's existence upon earth ? If there be, 

 it clearly would form a strong evidence in favor of the 

 doctrine, as what now takes place upon a confined scale 

 and in a comparatively casual manner, may have former- 

 ly taken place on a great scale, and as the proper and 

 eternity-destined means of supplying a vacant globe with 

 suitable tenants. It will at the same time be observed 

 that, the earth being now supplied with both kinds of 

 tenants in great abundance, we only could expect to find 

 the life-originating power at work in some very special 

 and extraordinary circumstances, and probably only in 

 the inferior and obscurer deparments of the vegetable and 

 animal kingdoms. 



Perhaps, if the question were asked of ten men of ap- 

 proved reputation in science, nine out of the number 

 would answer in the negative. This is because, in a 

 great number of instances where the superficial observers 

 of former times assumed a non-generative origin for life, 

 (as in the celebrated case in Virgil's fourth Georgic,) 

 either the direct contrary has been ascertained, or ex- 

 haustive experiments have left no alternative from the 

 conclusion that ordinary generation did take place, albeit 

 in a manner which escapes observation. Finding that an 

 erroneous assumption has been formed in many cases, 

 modern inquirers have not hesitated to assume that there 

 can be no case in which generation is not concerned ; an 

 assumption not only unwarranted by, but directly opposed 

 to, the principles of philosophical investigation. Yet this 

 is truly the point at which the question now rests in the 

 scientific world. 



I have no wish here to enter largely into a subject so 

 wide and so full of difficulties ; but I may remark, that 

 the explanations usually suggested where life takes its 

 rise without apparent generative means, always appear to 

 me to partake much of the fallacy of the petitio principii. 

 When, for instance, lime is laid down upon a piece ot 

 waste moss ground, and a crop of white clover for which 

 no seeds were sown is the consequence, the explanation 

 that the seeds have been dormant there for an unknown 

 fcime, and were stimulated into germination when the lime 



{>roduced the appropriate circumstances, appears extreme- 

 y unsatisfactory, especially when we know XaaX 'as io 



