254 SPECIAL HISTOLOGY. 



which the connective tissue is formed, but from special cells of 

 a temporary nature ; which circumstance, were the fact of 

 general application, would make it intelligible, that nuclear 

 fibres may both surround the secondary fasciculi of connective 

 tissue, and also exist without any such tissue (membranous, reti- 

 cular expansions of nuclear fibres, 'Mikr.Anat./ II, 1, p. 226).] 



B. Ligaments of the tendons. — The tendons are retained in 

 their positions by various ligaments. Independently of certain 

 ligamentous portions of the fasciae, which, being attached to the 

 bones, form tubular processes around tendons, or otherwise con- 

 fine them, there are the so-called tendinous sheaths [lig. vaginalia 

 tendinum), as for instance on the flexor tendons of the fingers 

 and toes, where they are formed of numerous successive narrow 

 bands, which in these situations serve to strengthen the 

 mucous sheaths. Other ligaments to be referred to this class, are 

 the lig. carpi proprium, the trochlea, and the retinacula tendinum. 



C. Mucous bursa and sheaths, — burses mucosa et vagina 

 synoviales. — "Where muscles or tendons, in their movements, rub 

 upon hard parts (bones, cartilages), or on other muscles, 

 tendons, and ligaments, there are found, between the parts in 

 question, spaces filled with a slightly viscid fluid, which, 

 according to Yirchow (Wurzb. 'Verh.' II, 281), contain not 

 mucus, but a material very similar to colloid matter, and 

 which anatomists have been used to regard as lined with 

 a special membrane, a synovial membrane. These spaces are 

 said to constitute closed sacs of a rounded or elongated form, 

 which either simply invest the opposed surfaces of bones and 

 tendons, bones and muscles, &c, — bursa mucosa; or in the form 

 of double, although connected tubes, cover at the same time 

 the surface of the tendons, and of the parts between which the 

 tendons play, — vagina synoviales. The truth of the matter is 

 this, that it is only the smallest of these spaces which are 

 lined with a continuous membrane; most of them are in 

 many situations without such a lining. With respect to the 

 mucous bursa, those appertaining to the muscles {psoas, iliacus, 

 deltoid, &c), are, eminently, to be considered as continuous 

 sacculi, whilst in those belonging to the tendons, a membrane 

 can only be detached in parts, and is found to be almost wholly 

 wanting exactly at the points where the mutually gliding parts 

 are in contact. Precisely the same thing obtains in the synovial 



