TISSUES OF THE BODY. 179 



elastic cartilage. In some parts, namely, these are homogeneous, and 

 then in others again the intercellular substance is traversed by elastic 

 fibres. The latter may be seen in the processus vocalis, and at times in 

 the tips. 



108. 



Elastic, reticular or fibro-reticular cartilages (fig. 169), which are 

 remarkable for their rather yellowish tint and great opacity, spring 

 from the hyaline cartilage of the foetal body. The development of their 

 elastic fibrillation reminds us thus of the formation of the chondrin- 

 yielding fibres of hyaline cartilage. It must be remembered, however, 

 that it is a process which belongs to the earlier periods of life, whilst the 

 appearance of fibres containing chondrin is an occurrence of a later time. 

 In young bodies the originally homogeneous constitution of the cartilage 

 may remain at particular points, especially in the vicinity of some of 



,., _ .. . Fie:. 170. Fibro-reticular carti- 

 r. 169. Reticular cartilage from the ear of !. t rrirn *hp human puio-int 



the calf, a, cells; 6, intercellular substance ; 

 c, elastic fibres of the latter. 



the cartilage cells. The fibres are at one time thin and delicate, at 

 another dark and irregularly bordered, with a very intricate course, reti- 

 culated or tangled like the fibres of felt. Wherever this fibrillation 

 is very strongly pronounced, the cells may be concealed to a great extent, 

 as, for instance, in the epiglottis (fig. 170), and pinna of the human ear. 

 The proportion of intercellular substance to the cells is also subject to 

 great variation, to such an extent at times that the latter may in one 

 instance be separated from one another only by narrow belts, or, on the 

 other hand, by a large quantity of interposed matter. The fibres are those 

 belonging to the elastic series, with the characteristic power of resisting 

 the action of reagents. They take their rise through an immediate meta- 

 morphosis of the homogeneous blastema without the intervention of 

 cells, as is indicated by the fact that in the human arytenoid cartilages 

 the homogeneous ground-substance is immediately continuous with the 

 fibrous. 



The cells of reticular cartilage, which vary greatly as to form and size, 

 are easier of isolation than those of the hyaline tissue. They are usually 

 scattered without any definite arrangement, although we may find in the 

 peripheral portions of the epiglottis small narrow elements, as in perma- 

 nent hyaline cartilage. The cells of reticular cartilage, farther, are often 

 remarkable for possessing less definite capsules and a less marked ten- 

 dency to the production of daughter-cells. The nuclei, which are either 

 smooth (in which case they contain a nucleolus), or granular, occur there- 

 fore single as a rule, or more rarely in pairs. In the body of the cell or 

 round about the nucleus fat may also be met with here. 



