220 
ANIMAL ACTIVITIES. 
How many bones compose the pelvic girdle ? 
By what kind of a joint is 
the femur attached to the 
pelvic girdle ? 
Drawing. Hind leg., 
naming bones. 
The Axial Skeleton. How 
many vertebrae compose the 
back-bone ? 
How many ribs are present ? 
How many of these are fast¬ 
ened to the sternum ? 
How does a mammalian 
vertebra compare with a verte¬ 
bra of a fish ? 
How does the vertebral 
column in a mammal differ 
from that in the frog ? 
The vertebra on which the 
skull moves is called the atlas, 
the vertebra next back of that 
is called the axis. Can you 
find on the atlas smooth sockets corresponding to pro¬ 
jections on the skull ? 
The projections on the skull are called condyles. 
How many condyles are there on the mammalian 
skull ? How many on the bird’s skull ? What purpose 
do condyles and sockets serve ? 
Do you find a quadrate bone on the mammalian 
skull ? 
What is the dental formula of the mammal you are 
studying ? 
What is the dental formula for the horse ? For a 
squirrel ? For a rabbit ? 
In the head of a horse, how does the area of face and 
cranium compare with the same areas in man ? 
(See figures.) Write resemblances and differences 
for skull of gorilla and man. 
Fig. 178. —Skeleton of Go¬ 
rilla. 
