"Cada uno es como Dios le hizo,

y aun peor muchas vezes."

"We are all as God made us

and many even worse."

Sancho Panza,

Don Quixote.

CHAPTER VII

REPTILIA

DEFINITION AND CHARACTERS–POSITION OF THE CLASS REPTILIA IN THE PHYLUM VERTEBRATA–CLASSIFICATION–SKULL AND VERTEBRAE.

The recent Reptiles comprise, broadly speaking, the Crocodiles, Tortoises, Lizards, and Snakes. They are the only Vertebrates which are cold-blooded, breathe by lungs, and have a median occipital condyle. Another equally sufficient diagnosis is the following:–Tetrapoda, with a median occipital condyle, with nucleated red blood-corpuscles, and with complete right and left functional aortic arches. A still shorter diagnosis is:–Monocondylia with a scaly skin.