THE RECORD FROM FOSSILS. 97 



Nine of the later appearing orders were insects which 

 fed upon flowers, and could only have appeared 

 after flowering plants ; and in general we notice that 

 the later appearing orders were largely land animals. 

 Besides the orders included in the above, there are 

 thirty-four which, from the soft structure of their 

 body, have left no traces in the rocks at any period. 

 Of these, it is certain that a number at least must 

 have been in existence in the Silurian (2), since their 

 close allies are known to exist there. Carrying our 

 study into smaller groups, and including now sub- 

 orders in our figures, we find the later ages coming 

 out in more prominence. Of the one hundred and 

 five orders and sub-orders that have left any evidence 

 of themselves in the rocks, forty-four are Silurian 

 and sixty-one have appeared in the later ages. Here 

 too we find that of the sixty-one later sub-orders 

 many are terrestrial, and at least twenty are insects-. 

 It is further noticed that the larger number of sub- 

 orders which are of recent origin belong to the 

 higher rather than the lower orders of animals. 

 Taking families into consideration, a larger number 

 were late in appearing, though a number of our 

 modern families date from the Silurian (2). 



Thus we see that the Archean age produced the 

 sub-kingdoms, the classes, and most of the orders of 

 animals, while the subsequent ages have only pro- 

 duced the smaller divisions, giving rise to a far less 

 divergence in type, but a much larger profusion of 

 minor branches. Now from all this it follows that 

 the study of fossils is unable to help us to the knowl- 

 edge of the early history of any of the sub-kingdoms 

 7 



