EYELID. 63 
Describe the layers of the cerebellum. 
The outer or molecular layer is composed of a delicate connective- 
tissue framework supporting fine nerve fibres and small fusiform and 
branching nerve cells. The middle or cellular layer is composed of a 
row of irregular-shaped branching cells (Purkinje's cells). The branch- 
ing processes ramify in the outer layer while the axis-eylinder passes 
inward through the inner layer. The inner, or granular layer, contains 
great numbers of small, round cells. This layer merges gradually into 
the white central substance of the cerebellum. 
Of what kind of tissue is the dura mater composed ? 
Of dense, fibrous tissue, with connéctive-tissue cells between the 
fibres, and contains numerous bloodvessels. Its inner surface is lined 
with a layer of endothelial cells. 
What is the structure of the pia mater? 
It is a thin membrane covered on its outer surface with a layer of 
endothelial cells. It is composed of connective tissue, and contains a 
very rich network of blood and lymph vessels. 
THE EYE. 
EYELID. 
Of what is the eyelid proper composed ? 
Of a plate of connective tissue which toward its free border becomes 
very dense and firm. This portion is called the tarsus or tarsal carti- 
lage; although it is not cartilaginous, but is composed of dense fibrous 
tissue. 
How is the eyelid covered externally ? 
On the outside by skin, which is beset with delicate hairs and con- 
tains sweat-glands and sebaceous follicles, It passes over on to the 
edge of the lid and meets the mucous membrane. In this free edge 
of the lid are inserted the eyelashes, having deep follicles which are 
furnished with sebaceous glands. 
How is the eyelid covered internally ? 
By a layer of mucous membrane which is reflected over from the 
eyeball. It is called the conjunctival mucous membrane, and consists 
of a loose fibrous structure containing elastic fibres and numerous round 
and branching cells. It is covered by stratified epithelium near the 
skin edge. 
