CONNECTIVE TISSUE. 63 



cells. Iii the later stages in the development of the arytenoid 

 cartilage there appear small granules which increase in size to 

 form the elastic granules of Ranvier. These do not form elastic 

 fibrils. O. Hertwig and Bubnoff hold that elastic fibres are a 

 product of the superficial layers of the cell protoplasm. Kurkow 

 claims that the fibres are formed in the protoplasm immediately 

 surrounding the nucleus, and that the nucleus influences this 

 formation. 



Fibrillar connective tissue may, according to the arrange- 

 ment of the fibril bundles and the density of the tissue, be 

 classified as: 1, loose or unformed; 2, dense or formed con- 

 nective tissue. 



1. In the first group the fibres form a loose network in which 

 cells of various kinds lie. This contains often large or small 

 groups of fat cells. It is distributed over the whole body, and 

 partly fills up the spaces between organs or their parts. It also 

 holds these organs or parts of organs together, as is plainly seen 

 in many parts of the body. 



2. In the second group the fibril bundles have a firm com- 

 bination and a regular arrangement. They may cross one 

 another at various angles, as, e. g., in the skin, the mucous 

 membranes, the periosteum, perichondrium, in the capsules of 

 many organs, etc. ; or they may be arranged in definite direc- 

 tions, and form firm strands and membranes. In the latter case 

 all the fibril bundles may run in one direction (e.g., in tendons), 

 or they may form flat sheaths whose fibres usually run at right 

 angles, as, e. g., in fascia and the cornea. 



In this way we have three kinds of connective tissue which 

 are merely modifications of fibrillar tissue, namely, white fibrous 

 tissue, elastic tissue, and fat tissue. 



(c) White fibrous connective tissue (Fig. 30) is merely a tissue 

 in which regularly arranged fibres of the sort described as white 

 connective- tissue fibres are the main constituents. It is found 

 most abundantly in tendons and fascia, but is to be seen in 

 smaller quantities in almost every part of the body. It has the 

 chemical properties described in speaking of the white fibrils, 

 and owes its name to its white appearance in the fresh condition, 



