250 VARIETIES OF CONNECTIVE TISSUE PROPER. [BOOK I. 



SECT. 1. CONNECTIVE TISSUE PROPER. 



structural By ^is term may be designated a tissue which pre- 



Eiements of sents many very important modifications in different 

 connective situations, and whose function it is to connect together 

 Tissue. contiguous organs or parts of the body, or actually to 



bind together the different anatomical elements which enter into the 

 composition of each organ. 



Typical connective tissue presents for examination : 



(1) Certain cells, which are especially abundant in the early 

 stages of development of the tissue, and which are termed connective 

 tissue cells or corpuscles. 



(2) Bundles of fine fibres of a white colour, arranged in 

 parallel rows ; or crossing one another, so as to leave spaces between 

 them ; or so interwoven as to give rise to tough fibrous membranes. 

 These fibres swell up and become so transparent as almost to dis- 

 appear from view when the tissue is treated with acetic acid. 



(3) Other fibres, usually much less numerous than the white, 

 presenting dark outlines, often intercommunicating by processes, 

 having when seen in large numbers a yellowish tint, and exhibiting 

 altogether distinct chemical reactions ; they are unacted upon by 

 acetic acid. These are the yellow, or elastic fibres of connective tissue. 



(4) A ground substance or matrix in which the other elements 

 are imbedded and which serves to connect them together, so 

 that we apply to it indifferently the name of ground substance, or con- 

 necting substance, or cement. 



By the preponderance of certain of these elements over others or 

 by the peculiar forms which certain of these elements may present, 

 the different varieties of connective tissue are distinguished. Thus, 

 for example, in 'white fibrous tissue,' of which tendons and ligaments 

 are formed, the white fibrillae preponderate over the other elements, 

 so that on superficial examination of the fully developed structures 

 neither cells nor yellow elastic elements are seen, and the structures 

 might be likened to cords formed of dense bundles of white fibrillae 

 firmly agglutinated together. Again in the yellow elastic ligaments, 

 such as the ligamentum nuchae of large herbivores, or the ligamenta 

 subftava of the human vertebral column, there is such a preponder- 

 ance of the yellow elastic over the white fibres, that the former confer 

 upon the structures their peculiar physical properties. 



In the adenoid or retiform connective tissue, by a peculiar modifi- 

 cation of the connective tissue cells, which give off branching pro- 

 cesses which join together, a network of fine fibres is established, 

 radiating at many points from connective tissue cells a network 

 admirably adapted to afford support to other structures. 



In the gelatinous connective tissue, the matrix or ground sub- 

 stance in which cells and fibres are imbedded is abundant and has a 

 'gelatinous consistence. 



