GENERAL ANATOMY OF THE FROG. 13 
Chap. I—GENERAL ANATOMY OF THE FROG. 
Fig. 1. The Common Frog (Rana temporaria): (from Kcker.) 
A. External Characters. 
Lay the frog on a board before you, and note the following 
pots :— 
1. The division into head, trunk, and limbs; and the absence 
of neck and tail. 
2. The two great surfaces ;— 
a, The dorsal surface, or back, directed upwards when 
the frog is in the natural position. 
b. The ventral surface, or belly, directed downwards 
towards the ground. 
3. The skin: moist and smooth: devoid of hairs, scales, or 
claws. The colour of the skin is variable in different specimens 
