xii.] THE ORIGIN OF SPECIES. 243 



modification of any other form of living matter or arising by 

 natural agencies but being produced, as such, by a supernatural 

 creative act. 



The other, the so-called &quot; transmutation &quot; hypothesis, considers 

 that all existing species are the result of the modification of 

 pre-existing species, and those of their predecessors, by agencies- 

 similar to those which at the present day produce varieties and 

 races, and therefore in an altogether natural way ; and it is a, 

 probable, though not a necessary consequence of this hypothesis, 

 that all living beings have arisen from a single stock. With 

 respect to the origin of this primitive stock, or stocks, the doctrine 

 of the origin of species is obviously not necessarily concerned. 

 The transmutation hypothesis, for example, is perfectly consistent 

 either with the conception of a special creation of the primitive 

 germ, or with the supposition of its having arisen, as a modifi 

 cation of inorganic matter, by natural causes. 



The doctrine of special creation owes its existence very largely 

 to the supposed necessity of making science accord with the 

 Hebrew cosmogony ; but it is curious to observe that, as the 

 doctrine is at present maintained by men of science, it is as 

 hopelessly inconsistent with the Hebrew view as any other 

 hypothesis. 



If there be any result which has come more clearly out of 

 geological investigation than another, it is, that the vast series of 

 extinct animals and plants is not divisible, as it was once sup 

 posed to be, into distinct groups, separated by sharply-marked 

 boundaries. There are no great gulfs between epochs and forma 

 tions no successive periods marked by the appearance of plants, 

 of water animals, and of land animals, en masse. Every year 

 adds to the list of links between what the older geologists 

 supposed to be widely separated epochs : witness the crags link 

 ing the drift with older tertiaries ; the Maestricht beds linking 

 the tertiaries with the chalk ; the St. Cassian beds exhibiting an 

 abundant fauna of mixed mesozoic and palaeozoic types, in rocks 

 of an epoch once supposed to be eminently poor in life ; witness, 

 lastly, the incessant disputes as to whether a given stratum shall 



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