124 RECENT ADVANCES IN NATURAL SCIENCE ix 



sequence is now generally recognised in the inorganic world ; 

 and although the modern expansion of this doctrine as applied 

 to the living inhabitants of the earth appears to many so 

 startling, and has met with so much opposition, it is, in a more 

 restricted application, a very old and widespread article of 

 scientific as well as of popular faith. 



Putting aside, as quite immaterial to the present discussion, 

 the still controverted question of the evidences of the production 

 of the lowest and most rudimentary forms of life from inorganic 

 matter, it may be stated as certain that there is no rational and 

 educated person, whatever his religious beliefs or philosophical 

 views, who is not convinced that every individual animal or 

 plant, sufficiently highly organised to deserve such distinctive 

 appellation, now existing upon the world, has been produced 

 from pre-existing parents by the operation of a series of 

 processes of the order to which the term natural is commonly 

 applied. These processes are also fundamentally the same 

 throughout the whole range of living beings, however much 

 modified in detail to suit the various manifestations under 

 which those beings are presented to us. We feel absolutely 

 certain, when we see a horse, a bird, a butterfly, or an oak-tree, 

 that each was derived from pre-existing parents, more or less 

 closely resembling itself. Though we may have no direct 

 evidence of the fact in each individual case, the knowledge 

 derived from the combined observations of an overwhelming 

 number of analogous cases is of such a positive character that 

 we should entirely refuse to credit any one who made the 

 contrary assertion, and should feel satisfied that he had been 

 deluded by some error of observation. We cannot, indeed, 

 conceive of the sudden beginning of any such creatures, either 

 from nothing, from inorganic matter, or even from other 

 animals or plants totally unlike themselves. 



To persons whose opportunities of observation of animal 

 and plant life are limited to a comparatively few kinds, 

 existing under comparatively similar circumstances, and which 

 observations moreover only extend over a comparatively limited 

 period of time, it appears that in each kind of animal or plant 

 such as those just mentioned, individuals of various succeeding 

 generations present a very close resemblance to each other. 



