362 THE EVOLUTION OF LIFE 



less distinct from German than Swedish is ; while betwaon 

 the Danish and Swedish there is so close a kinship, that they 

 might almost be regarded as widely-divergent dialects. 

 Similarly on comparing the larger divisions, we see that 

 the various languages of the Aryan stock, have deviated 

 from the original to very unlike distances. The geneial 

 conclusion is manifest. While the kinds of human speech 

 fall into groups, and sub-groups, and sub-sub-groups; yet 

 the groups are not equal to one another in value, nor have 

 the sub-groups equal values, nor the sub-sub-groups. 



If, then, the classification of organisms results in several 

 orders of assemblages, such that assemblages of the same 

 order are but indefinitely equivalent ; and if, where 

 evolution is known to have taken place, there have arisen 

 assemblages between which the equivalence is similarly in- 

 definite ; there is additional reason for inferring that 

 organisms are products of evolution. 



126. A fact of much significance remains. If groups 

 of organic forms have arisen by divergence and re-diver- 

 gence ; and if, while the groups have been developing 

 from simple groups into compound groups, each group and 

 sub-group has been giving origin to more complex forms 

 of its own type ; then it is inferable that there once ex- 

 isted greater structural likenesses between the members of 

 allied groups, than exist now. Hence, if we take the 

 simplest members of any group to be those which have 

 undergone the least change ; we may expect to find a greater 

 likeness between them and the simplest members of an allied 

 group, than we find between the more complex members 

 of the two groups. This, speaking generally, proves to 

 be so. 



Between the sub-kingdoms, the gaps are extremely wide ; 

 but such distant kinships as may be discerned, bear out an- 

 ticipation. Speaking of that extremely-degraded vertebrate 

 animal the Amphioxus, which has several molluscous traits 



