180 GENERAL DISCUSSION [ch. xiv 



the same character, and that in perfection, should so often be 

 found at widely separated places in the same family, and not 

 only so, but also at numerous places in other families and in 

 other classes. There is no morphological difference in a berry, 

 whether it be found in the Dicotyledons or in the Monocotyledons. 



Only the conception, which is so largely borne out by the facts, 

 that mutations on the whole were larger the further back into 

 the past that one goes, from species through genus to family and 

 class, can easily explain the remarkable fact that this is definitely 

 the case, as both differences, and impossibility of transitions, 

 increase together. Neither in life nor in the fossils do we find any 

 evidence of serious transitional stages, and it is therefore evident 

 that the further back we go from the individual the greater are 

 the differences, whereas natural selection cannot be shown to be 

 more and more efficient in destroying transitions upon the same 

 route. 



We have now to consider the actual differences seen between 

 organisms. There is no doubt that specific differences are usually, 

 but 7iot necessarily, small (p. 79), while generic are on the whole 

 larger, though there are large differences between different kinds 

 of genera, as for example between those of small families and those 

 of large (p. 110). Family differences are on the whole the largest 

 of the three. Looking at the list of family characters in Appen- 

 dix I, one notices their divergence when taken in pairs — alternate 

 or opposite leaves, cymose or racemose inflorescence, and so on. 

 Many of these pairs do not allow of intermediates or transitions, 

 but this shows less in generic or specific characters. Practically 

 all of the family characters, however, may at times appear as 

 generic or specific ; there is nothing about a character to place it 

 only in one of these classes. In fact, as we have seen on p. 110, 

 the rank of genera or of species differs with the size of the groups 

 to which they belong. 



One may almost say that a family has a combination of most of 

 these "family" characters, though sometimes the one, sometimes 

 the other, of any particular divergent pair. The important points 

 are this divergence, and the fact that the character is shown in 

 full perfection (p. 114), a feature that one would certainly not 

 expect under the operation of natural selection, for the adapta- 

 tional value of the character would diminish as it approached 

 perfection, and probably 95 per cent or less would be as good as 

 100 per cent. It is all but inconceivable that selection should 

 produce perfection in a character, especially one like most 



