THE OLDEST AIR-BREATHERS 275 



was, in short, as we often find to be the case with the earliest 

 forms of life, the possessor of powers and structures not usu- 

 ally, in the modern world, combined in a single species. It 

 was certainly not a fish, yet its bony scales and the form of its 

 vertebrae, and of its teeth, might, in the absence of other evi- 

 dence, cause it to be mistaken for one. We call it a Batrachian, 

 yet its dentition, the sculpturing of the bones of its skull, 

 which were certainly no more external plates than the similar 

 bones of a crocodile, its ribs, and the structure of its limbs, 

 remind us of the higher reptiles ; and we do not know that it 

 ever possessed gills, or passed through a larval or fish-like 

 condition. Still, in a great many important characters, its 

 structures are undoubtedly batrachian. It stands, in short, in 

 the same position with the Lepidodendra and Sigillarice under 

 whose shade it crept, which, though placed by palaeobotanists 

 in alliance with certain modern groups of plants, manifestly 

 differed from these in many of their characters, and occupied 

 a different position in nature. In the coal period the distinc- 

 tions of physical and vital conditions were not well defined. 

 Dry land and water, terrestrial and aquatic plants and animals, 

 and lower and higher forms of animal and vegetable life, are 

 consequently not easily separated from each other. This is 

 no doubt a state of things characteristic of the earlier stages of 

 the earth's history, yet not necessarily so ; for there are some 

 reasons, derived from fossil plants, for believing that in the 

 preceding Devonian period there was less of this, and conse- 

 quently that there may then have been a higher and more 

 varied animal life than in the coal period. ^ 



The dentition of Dendrerpeton shows it to have been car- 

 nivorous in a high degree. It may have captured fishes and 

 smaller reptiles, either on land or in water, and very probably 

 fed on dead carcases as well. If, as seems likely, any of the 



^ See the author's paper on Devonian plants, /ournal of the Geological 

 Society, vol. xviii. p. 328. 

 14 



