AFFINITIES AND CLASSIFICATION 35 



vii. (AFFINITIES AND CLASSIFICATION.) 



Looking now to the affinities of organisms, with- 

 out relation to their distribution, and taking all 

 fossil and recent, we see the degrees of relationship 

 are of different degrees and arbitrary, sub-genera, 

 -genera, sub-families, families, orders and classes 

 and kingdoms. The kind of classification which 

 everyone feels is most correct is called the natural 

 system, but no can define this. If we say with 

 Whewell (that we have an) undefined instinct of the 

 importance of organs 1 , we have no means in lower 



Finally, as continent (most extinction (?) during formation of continent) 

 is formed after repeated elevation and depression, and interchange of species 

 we might foretell much extinction, and that the survivor would belong to 

 same type, as the extinct, in same manner as different part of same continent, 

 which were once separated by space as they are by time (see Origin, Ed. i. 

 pp. 339 and 349). 



As all mammals have descended from one stock, we ought to expect that 

 every continent has been at some time connected, hence obliteration of 

 present ranges. I do not mean that the fossil mammifers found in S. 

 America are the lineal successors (ancestors) of the present forms of S. 

 America : for it is highly improbable that more than one or two cases (who 

 will say how many races after Plata bones) should be found. I believe 

 this from numbers, who have lived, mere (?) chance of fewness. Moreover 

 in every case from very existence of genera and species only few at one time 

 will leave progeny, under form of new species, to distant ages ; and the more 

 distant the ages the fewer the progenitors. An observation may be here 

 appended, bad chance of preservation on rising island, the nurseries of new 

 species, appeal to experience (see Origin, Ed. i. p. 292). This observation 

 may be extended, that in all cases, subsiding land must be, in early stages, 

 less favourable to formation of new species ; but it will isolate them, and 

 then if land recommences rising how favourable. As preoccupation is bar 

 to diffusion to species, so would it be to a selected variety. But it would 

 not be if that variety was better fitted to some not fully occupied station ; 

 so during elevation or the formation of new stations, is scene for new 

 species. But during elevation not favourable to preservation of fossil 

 (except in caverns (?)) ; when subsidence highly favourable in early stages to 

 preservation of fossils ; when subsidence, less sediment. So that our strata, 

 as general rule will be the tomb of old species (not undergoing any change) 

 when rising land the nursery. But if there be vestige will generally be 

 preserved to future ages, the new ones will not be entombed till fresh subsi- 

 dence supervenes. In this long gap we shall have no record : so that 

 wonderful if we should get transitional forms. I do not mean every stage, 

 for we cannot expect that, as before shown, until geologists will be prepared 

 to say that although under unnaturally favourable condition we can trace 

 in future ages short-horn and Herefordshire (see note 2, p. 26). 



1 After " organs " is inserted, apparently as an afterthought : " no, and 

 instance metamorphosis, afterwards explicable." 



