CONNECTIVE TISSUE. 



191 



coagulating liquid, which has an odor similar to that of glue, but 

 is not viscid. The reticulum of living matter is infiltrated with 

 this so-called " chondrogenous n basis-substance, the cavities of 

 which hold plastids varying greatly in size, number, and config- 

 uration. In the juvenile condition of the individual, the plastids 

 are generally solid and homogeneous ; in the middle-aged they 

 are distinctly nucleated, exhibiting a very fine reticulum of living 

 matter. That these plastids 

 in the living tissue are 

 alive, I was the first to dem- 

 onstrate (page 116). Carti- 

 lage, as well as other vari- 

 eties of connective tissue, 

 should be preserved in a 

 solution of chromic acid; 

 to examine fresh cartilage 

 kept in pure water is very 

 objectionable, as in this 

 liquid the plastids soon 

 become vacuoled and de- 

 stroyed. 



We distinguish three 

 varieties of cartilage, which 

 may be arranged according 

 to the order in which they 

 approach the structure of 

 fibrous connective tissue: 

 reticular or elastic carti- 

 lage ; fibrous or striated car- 

 tilage 5 hyaline cartilage. 



fa) Reticular or Elastic 

 Cartilage resembles the re- 

 ticular variety of myxoma- reticular arrangement; the reticulum surrounds the 



tous connective tissue. The 

 difference is that its basis- 

 substance, instead of being mucous, is dense and chondrogenous, 

 and is traversed in an apparently irregular manner by very dense, 

 bright, elastic fibers. Owing to the presence of this elastic re- 

 ticulum, the tissue has a yellowish color and a high degree of 

 pliability. (See Fig. 72.) 



The elastic fibers, as a rule, are very delicate, and sometimes 

 are packed closely together in slender bundles, their width vary- 



FIG. 72. RETICULAR CARTILAGE FROM 

 THE EPIGLOTTIS OF A CHILD. CHROMIC 

 ACID SPECIMEN. 



C, hyaline cartilage traversed by fibers, R, in a 



territories of the cartilage corpuscles ; P, perichon- 

 driura. Magnified 500 diameters. 



