BRITISH ANIMALS. 
VERTEBRAL ANIMALS. 
I. WARM-BLOODED VERTEBRAL ANIMALS. 
The temperature of the body independent of the sur- 
rounding medium. Ribs and sternum for the pro- 
tection of the viscera. The Brain occupies the whole 
cavity of the skull. Passage of the nose communi- 
cates with the windpipe. Heart double, and the cir- 
' culation complete. 
Class I. MAMMALIA. 
Class II. BIRDS 
{ 
{ 
Young suckled by the mother. 
Ovarium double. Covering of 
hair. 
Young supported by food collected 
by the mother. Ovarium single. 
Covering of feathers. 
'II. COLD-BLOODED VERTEBRAL ANIMALS. 
Temperature of the body under the influence of the sur- 
rounding medium. Skin destitute of hair or feathers. 
The brain does not occupy the whole cavity of the 
skull. Circulating system imperfect. 
r Furnished with a systemic heart. In 
Class I. REPTILES. general breathe air in their perfect 
i. state. 
{ Destitute of a systemic heart. Fur^ 
Class II. FISHES.... nished with gills. Reside in wa- 
V ter. 
