MEMBRANE. 
117 
TABULAR VIEW OF THE ANIMAL TISSUES. 
1. Simple membrane : employed alone or') Examples 
in the formation of compound mem- 
branes 
6. 
Walls of cells. Posterior layer 
of the cornea. Capsule of lens. Sar- 
colemma of muscle, &c. 
("White and yellow fibrous tissues. Areolar 
* | tissue. Elastic tissue. 
(" Cartilage. Adipose tissue. Pigment. Grey 
• ( nervous matter. 
( Rudimentary skeleton of invertebrata. Bone. 
‘ * ( Teeth, &c. 
~ . composed oL 
simple membrane, and a layer of cells ) ,, , 0 , . , 
(Mucous membrane. Serous and synovial 
membranes. True or secreting glands. 
2. Fibrous tissues 
3. Cellular tissues 
Sclerous or hard tissues 
Compound membranes: 
■s 
of various forms, (epithelium or epider- 
mis,) or of areolar tissue and epithe 
lium ...... 
Compound tissues : a, composed of b 
tubes of homogeneous membrane con- > Muscle. Nerve, 
taining a peculiar substance . .) 
b. Composed of white fibrous tissues*! 
and cartilage . . . J Fibro-cartilage. 
MEMBRANE. 
Membrane is thin, transparent, and structureless, 
it never presents any visible pores, although fluids 
pass through it readily ; wherever it exists, it is 
more or less nourished by blood-vessels, which run 
on its outer surface, but never enter it. The posterior 
layer of the capsule of the lens of the eye of a 
Sheep , affords an excellent example of this elementary 
tissue, which is completely structureless, and as trans- 
parent as glass, having no trace of cell in or upon it, 
so that its very presence can only be discerned by 
accidental folds, or other irregularities. The capsule 
of the lens, especially its posterior layer, is in early 
life, very vascular, that is to say, vessels ramify freely 
on its surface, but they do not enter into its forma- 
