WHITE FIBROUS TISSUE. 



279 



Fig. 177. 



ments), or are found developed in the tendons, tendinous sheaths, 

 and the ligaments. 



4. The fibrous membranes, so called, differ from the tendons only 

 by the frequent interweaving of the bundles, to give them their 

 difference in form, and by the greater amount of elastic fibres. 

 Under this head may be mentioned 



.First. The deepfascice (femoral, &c.), which very nearly resemble 

 the aponeuroses in structure, and some of which are classed with 

 them. 



Secondly. The periosteum and perichondrium, which sometimes 

 contain a great number of elastic fibres, are more vascular than 

 the preceding, and are sparingly supplied with nerves and lymph- 

 atics. The dura mater also belongs here, it 

 being the internal periosteum (endosteum) of 

 the cranium, while it at the same time protects 

 the encephalon. 



5. The white, dense tunics included under the 

 second head, except the cornea viz : the fibrous 

 tunic of the testes and ovaries, penis and clitoris, 

 and the fibrous envelop of the spleen and kid- 

 neys consist of solid white fibrous tissue, with 

 elastic fibres interwoven. In the case of these 

 organs, also, the fibrous layer projects into the 

 interior, where, mixed to a greater or less ex- 

 tent with smooth muscular fibres, it constitutes Section of testis. i. ca- 



vity of tunica vaginalis. 2. 



dissepiments or a kind of framework, or forms Tunica aibuginea. 3. Medi- 

 a stroma or a trabecular network. The object ^cSl^ t^tSel^which 

 here is to inclose and protect the parenchyma are the lobules (5) of semi- 

 of the organs in question. The sclerotica, how- 

 ever, has no such internal projections ; and the 

 perineurium is homogeneous in structure, as 

 has been already stated (p. 276). Fig. 177 shows the fibrous tra- 

 beculae in the testis, radiating from the mediastinum. 



6. The so-called vascular membranes the pia mater, choroid 

 plexus, the choroid coat of the eye, and the iris all have numerous 

 vessels ; for the nutrition, however, especially of other parts. They 

 vary in structure. The iris and the pia mater have parallel, matted, 

 and anastomosing bundles of white fibres, without any elastic tis- 

 sue. The choroid plexus and the choroid membrane of the eye, 



niferous tubes. 4. Pia ma- 

 ter testis. 6. Epididymis, 

 and below it the corpus 

 Highmorianum, above 3. 



