44 



COMPARATIVE ANATOMY 



CHAP. 



remain round ; they generally assume a long spindle shape or a branched 

 form. In the last case there again arises a sort of retieular connect- 

 ive tissue. The processes of the cells themselves are often differenti- 

 ated into fibres, which associate themselves with those formed from 

 the intercellular substance. Fibrous connective tissue may have a 

 loose texture or a firm texture, as in tendinous tissue (Fig. 41). The 

 fibres swell on treatment with acids and alkalis. If they are elastic 

 and retieular, and if they do not swell under the influence of acids 

 and alkalis, we have elastic connective tissue. 





Ill 



FIG. 41. Tendinous tissue, from the 

 longitudinal section of a sinew, after 

 Gegenbauer. 



FIG. 42. Hyaline cartilage. To the right above 

 are depicted the protoplasmic threads which connect 

 the cartilage cells. 



Cells of connective tissue may become pigment cells by the deposi- 

 tion of colouring material. 



Cartilaginous tissue is a very good instance of the structure and 

 rise of real connective tissue. The cells generally remain round. 

 They secrete membranes, which continually become thicker and 

 stronger by their own growth, and which finally mingle with those of 

 the neighbouring cells and form a tolerably firm intercellular substance, 

 the cartilaginous substance, which in boiling yields chondrine. The 

 cartilage cells continue to divide ; the daughter cells again surround 

 themselves with membranes. Sometimes the membranes of various 

 generations can still be distinguished the less easily, of course, the 

 older they are (Fig. 42). 



If the cartilaginous substance is homogeneous and structureless we 

 have hyaline cartilage ; if it is fibrous we speak of fibrous cartilage. 

 In cartilaginous tissue also the intercellular substance seems penetrated 

 by exceedingly fine processes of the cartilage cells, which apparently 



