THE PROTOPLASM A AND THE CELL. 



17 



vessels, the capillaries, were formed of cemented, elongated 

 cell lamellae which become curved and joined together as a 

 tube (Fig. 21). 



Stellate cells (Fig. 22), may blend together through their 

 processes, and form a very delicate net-work. The meshes 

 may be filled up with homogeneous gelatinous matter, and 

 also with a multitude of lymphoid cells. In the former case 

 we again have a variety of intercellular substance. 



The latter acquires a considerable thickness in many tissues, 

 as in cartilage. At first (Fig. 23), this intermediate substance 

 is homogeneous throughout. This condition is either main- 



Fig. 2 j. — Cartilage of a 

 young sheep toetus. 



Fig. 74. — Cartilage from the auricle of a calf's 

 ear ; a, cells , b, intercellular substances ; c, 

 elastic fibres of the latter. 



tained, or else fibres subsequently shoot out from the inter 

 cellular substance. Frequently (Fig. 24), we 

 meet with them crossed in a felt-like or reticu- 

 lated manner. They present an obstinate 

 power of resistance to reagents. Such fibres 

 are called elastic. Therefore— we repeat it— 

 the elastic fibre is the result of a subsequent 

 metamorphosis of an originally homogeneous 

 substance. 



Connective tissue is infinitely diffused 

 through the human body. A small piece of 

 this, taken from the embryonic body, shows us, 

 together with cells, bundles of very fine 

 fibrillae, the connective-tissue fibres (Fig. 25). 

 They have a quite similar origin. Subsequently, the con- 



FlG. 25. — From the 

 tendon of a hog's em- 

 bryo ; <i, the cell ; /', 

 connective tissue fi- 

 brillae. 



