108 



SIMPLE HISTOLOGICAL ELEMENTS. 



Fig. 46. 



part of its mass, and giving it its hardness. (Q-luge, p. 37.) It is, 

 also, one of the elements of tubercle. 



From its structureless appearance, and its transparency when 

 seen in section, it has also been termed hyaline substance. 1 In rela- 

 tion to the other elements of compound tissues, it is sometimes 

 termed a homogeneous matrix, in which the other elements (cells, 

 fibres, &c.) are said to be imbedded. 



In some cases, however, minute granules appear in this histo- 

 logical element. Its two forms, therefore, are the hyaline and the 



granular homogeneous sub- 

 stance. When in its lowest 

 form, as in some cancers, it 

 seems to be mere coagulated 

 albumen. In the tissues, how- 

 ever, the homogeneous sub- 

 stance appears always to have 

 attained to a higher stage than 

 mere albumen, though it is 

 very probably always deve- 

 loped from that element in the 

 blood. For example, the ho- 

 mogeneous matrix of cartilage 

 contains cartilageine, and not 

 albumen, while that of bone 

 and dentine contains osteine only. On the other hand, some can- 

 cerous deposits afford merely albuminous products on being boiled, 

 while others afford gelatine, and thus show that osteine existed in 

 them. In the latter case, however, there are fibres of white fibrous 

 tissue, as well as homogeneous substance, in the cancerous deposit, 

 and this tissue may have afforded all the gelatine to the boiling 

 water (p. 98). 



Origin. If the lowest form of homogeneous substance, whether 

 granular or not (as in cancer), appears to be simply coagulated albu- 

 men, it is really something more something possessed of vital 

 endowments in all the tissues ; though probably formed from the 

 albumen of the blood, in each of them, by assimilation. 



Functions. In its lowest form, it, therefore, hardly does more 

 than serve as a cement to connect other histological elements to- 



Homogeneous substance and cells of cartilage a. 

 Group of four cells, separating from each other. 6. 

 Pair Of cells in apposition, c, c. Nuclei of cartilage 

 cells, d. Cavity containing three cells. The granu- 

 lar homogeneous substance is seen between the cells. 



1 From 'uaXo;, glass, it resembling a lamina of this substance. 



