CHARLKS DARWIN. 125 



than the norilla differs from tlie other apes; that in cranial capacity 

 rueu ditfer more from one another than they do from the apes, and 

 no more from the apes than the apes differ from one another ; that 

 the differences between the skull of man and that of the gorilla are 

 less than those between the skull of the gorilla and that of some 

 other apes ; and that the dentition of man differs less from that of 

 the higher apes than the dentition of the higher apes differs from 

 that of the lower apes. And he finally sums up the results of his 

 comparison with this remark : — " Thus, whatever system of organs 

 be studied, the comparison of their modifications in the ape series 

 leads to one and the same result — that the structural differences 

 which separate man from the goi'illa and the chimpanzee are not so 

 great as those which separate the gorilla from the lower apes." 



If we had, in the rocks, a complete epitome of the history of our 

 earth and its inhabitants, no doubt the pedigree of all our plants 

 and animals, including that of man, might be traced as certainly as 

 in the case of the horse, but the strata now existing, as Darwin 

 has shown, are but fragments of the deposits which have been 

 formed, and the fossils we find in them are but hap-hazard samples 

 of the organisms which have been entombed. Our rocks are worn 

 away by the action of water, and the sediment is carried into the 

 sea, but only to form new rocks which are upraised and have no 

 sooner become dry land than they are again worn down by rain 

 and rivers, this process continually recurring, so that we only here 

 and there catch a glimpse of the past in the strata which have 

 escaped denudation, and in these strata we only here and there 

 find a fossil, or a group of fossils, which has escaped destruction 

 or obliteration. Nevertheless missing links are constantly being 

 discovered, — links between mammals and amphibians, between 

 birds and reptiles, between amphibians and fishes, and even 

 between the Vertebrata and the Invertebrata (through the 

 Tunicata) ; and also innumerable links between genera and 

 species, so that it is getting more and more difficult to define 

 a species, they run so imperceptibly one into another. 



As Evolution is now an established doctrine, it is needless to 

 multiply evidences of genetic relationship : but the question is 

 yet to be considered as to how far Darwin's theory of natural 

 selection is adequate to explain how evolution has taken place. 



Most of the pre-Darwinian evolutionists considered that all living 

 things possess an inherent faculty of progressive development, but 

 the acceptance of such a view as an efficient cause of progress is 

 almost as likely to stifle investigation as is the belief in special 

 creation. It will be sufficient to give a brief outline of the views 



