This is a class of animals between birds and fishes, generally crawling
or swimming, of a cold temperature, sluggish habits, slow digestion,
and obtuse senses. They include serpents, lizards, tortoises, frogs,
toads, salamanders, the proteus and siren. The reptilia are divided
into four orders, the division being founded upon the difference in the
quantity of their respiration, and the diversity of their organs of
motion.