240 



THE TISSUES. 



Fig. 146. 



leaves the ovary. They contain yellowish fatty granules, which 

 become indistinct after the death of the animal. (Fig. 145.) 



The epithelial lining of serous membranes (Fig. 140) gives their 

 surface a glassy lustre, and lubricates it by its secretion. A part, 

 however, of the serum in serous cavities the water more espe- 

 cially doubtless enters them by mere transudation from the blood- 

 vessels. In inflammations the epithelium is detached, and the sur- 

 face of the membrane then becomes somewhat rough, and of a dull, 

 leaden hue. 



Kolliker asserts that this kind of epithelium is, in the ventricles 

 of the brain of embryos, surmounted with cilia. 



B. Compound Scaly Epithelium. 

 This kind of epithelium consists of several layers of cells, the 



outermost of which assume the form of dry scales, or become very 



much flattened cells. (Fig. 146.) 



Distribution. Compound scaly epithelium covers the synovial 



membranes generally. On the mucous membrane it is found lining 

 the alimentary canal from the lips to the 

 cardiac orifice of the stomach, and the lower 

 half or more of the rectum. It also extends 

 into the nostrils a short distance, and lines 

 the lachrymal canals, the conjunctiva, and 

 the cavity of the tympanum, except the 

 inner surface of the membrana tympani. . 

 It extends through the female urethra, the 

 vagina, and the lower third of the cavity of 

 the uterus (but not through its neck), and 

 covers the clitoris and nympha3. Finally, it 

 lines the bladder, ureters, and pelvis of the 

 kidneys, in both sexes. 



The compound scaly epithelium also eve- 

 rywhere forms the outer layer of the skin, 

 and is here called the epidermis. In the 

 latter the scales are dry and horny, as before 

 stated. Figs. 146 and 68 show its vertical 

 vertical section of epidermis section ; the entire epithelium of the skin 



'SSSSSSi^SSSi including both the epidermis and the rete 



b. inner portions, of nucleated mucosum, as it is improperly called. 



cells, c. Portion of perspiratory . 



duct. (Magnified 155 diameters.) Peculiarities. The epithelium of the skin 



