LIFE'S ANOMALIES 23 



curious circumstance that the drama of life should 

 have followed the same course at different periods 

 of geological time, although the personnel, so to 

 speak, of the actors has been altogether different. 

 During the Mesozoic epoch, for instance, mammals 

 were few and of a backward or unspecialized kind, 

 and the lead in the animal kingdom was taken by 

 enormous reptiles, of which our lizards and turtles 

 are the degenerate survivors. Yet we find that 

 to those reptiles parts were distributed which 

 resembled very closely those now taken by mam- 

 mals. Some were carnivorous, others were herbi- 

 vorous : some, like bats, haunted the air ; and 

 others, like whales, the sea. A similar generaliza- 

 tion may be made of the plants which flourished 

 at the time the coal measures were formed. 

 Timber trees occurred rarely ; their places were 

 taken by gigantic ferns and club -mosses, some of 

 which stood 60 feet high. It is a striking tact that 

 these plants grew, not by annual additions to 

 their tips, like the existing degenerate ferns and 

 club- mosses, but by the formation of annual rings 

 round the stem after the fashion, that is to say, 

 of timber trees. Life has repeated its functions 

 with organisms which have differed very widely in 

 physical development, and we seem to be in the 

 presence of an energy that can act independently 

 of form. We have reason to conclude that a living 

 creature is in fact constituted by the union of two 

 very different elements, one of which Matter is 

 subject to such natural laws as those of gravity 

 and chemical reaction, whilst the other Life 

 may entirely disregard them. 



