ON ZOOLOGY. 107 



tion more particularly to anatomical investigations 

 than Linnaeus, noticed with great truth the dis- 

 criminating varieties which exist in the cerebral 

 or nervous system, as well as in the circulating 

 organs of animals ; and that all red blooded 

 animals have a cranium, in which is contained 

 a brain, and a vertebral column containing a 

 spinal marrow, from both of which the nerves 

 emanate ; and therefore these, embracing the 

 four first classes, or more perfect animals of Lin- 

 naeus, he has denominated vertebral. And that 

 all white blooded animals, as insects and worms, 

 have not only doubtful respiratory and circulat- 

 ing organs, but have also a deficiency, or rather 

 want of vertebral canal ; and such animals he 

 has in consequence classed under the head of 

 inverlebral animals. From these two grand dis- 

 tinctions, he has formed his subdivisions, classes, 

 orders, and genera, into which he has entered 

 more copiously than his predecessor, Linnaeus. 



Blumenbach has adopted the classification of 

 Linnaeus, but has deviated both from that natu- 

 ralist and from Cuvier in many of his orders ; in 

 which he has adverted not only to the varieties 

 in the external structure of animals, but also to 

 their voluntary organs. 



The suggestions of such distinguished natural- 

 ists as Cuvier and Blumenbach, cannot fail to 

 improve most importantly the science of natural 

 history ; but until the whole of the existing 



