136 ADIPOSE TISSUE. 



The instances of yellow fibrous tissue are : the ligamenta subflava of 

 the arches of the vertebrae, cordae vocales, thyro-epiglottic ligament, crico 

 thyroidean membrane, the membranous layers connecting the cartilaginous 

 rings of the trachea and bronchial tubes, the capsula propria of the spleen 

 and the middle coat of arteries. It is also met with around some parts of 

 the alimentary canal, as the oesophagus, cardia, and anus, around the male 

 and female urethra, in the fascia lata, and in the corium of the skin. 



Red fibrous tissue is also termed contractile tissue, from a peculiar pro- 

 perty which it possesses, and which places it physiologically in an inter- 

 mediate position between white fibrous tissue and muscular fibre. Its 

 fibres are cylindrical, transparent, reddish in hue, and collected into fasci- 

 culi. It is met with in the corium of the skin, in the dartos, around the 

 nipple, in the excretory ducts of glands, in the coats of blood-vessels, 

 particularly veins, in the iris, in the intervascular spaces of the erectile 

 tissue of the penis and clitoris, around the urethra, and around the vagina. 



ADIPOSE TISSUE is composed of minute cells, 

 aggregated together in clusters of various size 

 within the areolaB of fibro-cellular tissue. The 

 cells of adipose tissue are identical in manner of 

 formation with other cells, being developed on 

 nuclei and increasing in size by the formation of 

 fluid in their interior. In adipose cells this fluid, 

 instead of being albuminous as in other cells, is 

 oleaginous, the oil at first appearing in separate 

 globules, which subsequently coalesce into a sin- 

 gle drop. The size of adipose cells at their full 

 development is. about 7 J<j of an inch in diameter ; 

 when isolated they are globular in form, but are 

 nexagonal or polyhedral when compressed. They are perfectly transparent, 

 the cell-membrane being structureless and their nucleus disappearing as 

 they' attain their full size. 



SYNOVIAL MEMBRANE is a thin membranous layer, which invests the 

 articular cartilages of the bones, and is thence reflected upon the surfaces 

 of the ligaments which surround and enter into the composition of a joint. 

 It resembles the serous membranes in being a shut sac, and secretes a 

 transparent and viscous fluid, which is named synovia. Synovia is an 

 alkaline secretion^containing albumen, which is coagulable at a boiling: 

 temperature. The continuation of this membrane over the surface of trre 

 articular cartilage, a much-agitated question, has been decided by the in- 

 teresting discoveries of Henle, who has ascertained the existence of an 

 epithelium upon cartilage identical with that produced by the reflected 

 portion of the membrane. In some of the joints the synovia! membrane 

 is pressed into the articular cavity by a cushion of fat : this mass was called 

 by Havers the synovial gland, from an incorrect supposition that it was 

 the source of the synovia ; it is found in the hip and in the knee-joint. 

 Jn the knee-joint, moreover, the synovial membrane forms folds, which 

 are most improperly named ligaments, as the mucous and alar ligaments, 

 the two latter being an appendage to the cushion of fat. Besides the 



* Fat vesicles, assuming the polyhedral form from pressure against one another. The 

 capillary vessels are not represented. From the omentum : magnified about 300 dia- 

 meters 



