CLASSES OF VEETEBRATA. 195 



Finally, the palseontologieal records of creation are also 

 of especial value in the case of these same Vertebrate 

 animals ; for their fossil remains belong for the most part 

 to the bony skeleton, a system of organs which is of the 

 utmost importance for understanding their general organiza- 

 tion. It is true that here, as in all other cases, the fossil 

 records are exceedingly imperfect and incomplete, but more 

 important remains of extinct Vertebrate animals have been 

 preserved in a fossil state, than of most other groups of 

 animals ; and single fragments frequently furnish the most 

 important hints as to the relationship and the historical 

 succession of the groups. 



The name of Vertebrate Animals (Vertebrata), as I have 

 already said, originated with the great Lamarck, who 

 towards the end of the last century comprised under this 

 name, LiniiEeus' four higher classes of animals, viz. Mammals, 

 Birds, Amphibious animals, and Fishes. Linnaeus' two lower 

 classes, Insects and Worms, Lamarck contrasted to the 

 Vertebrata as Invertehrata, later also called Evertebrata. 



The division of the Vertebrata into the four classes above 

 named was retained also by Cuvier and his followers, and 

 in consequence by many zoologists down to the present 

 day. But in 1822 BlanviUe, the distinguished anatomist, 

 found out by comparative anatomy — which Bar did almost 

 at the same time from the ontogeny of Vertebrata — that 

 Linnaeus' class of Amphibious animals was an unnatural 

 union of two very different classes. These two classes were 

 separated as early as 1820, by Merrin, as two main groups 

 of Amphibious animals, under the names of Pholidota and 

 Batraehia. The Batrachia, which are at present (in a 

 restricted sense) called Amphibious animals, comprise Frogs, 



