CELLULAR OR FIBROUS TISSUE. 329 



which a loose skein of silk is often observed to fall. (See 

 Plate XXXIX. fig. 6.) 



When dried, the inelastic cellular tissue assumes the trans- 

 parent appearance and consistence of horn : in water the 

 fibres swell up somewhat, become opaque and white, but still 

 preserve their form: in acetic acid they swell up greatly, 

 become indefinable, soft, and gelatinous: the addition of a 

 mineral acid will, however, bring the fibres again into view. 



The remarkable effect of acetic acid on the inelastic fibrous 

 tissue has suggested the idea to Mr. Bowman that (( it is 

 rather a mass with longitudinal parallel streaks (many of 

 which are Greasings), and which has a tendency to slit up 

 almost ad infinitum in the longitudinal direction." 



There are several considerations which may be urged in 

 disproof of this view ; the first is, the mode of development 

 belonging to this tissue ; the second, the fact that the fibres 

 are all of nearly an equal diameter ; and the third is, that the 

 tissue still retains its fibrous constitution even after the ap- 

 plication of acetic acid. 



The white fibrous tissue is employed wherever a strong 

 and inelastic material occupying but little space is required. 



A degree of elasticity not unfrequently appears to belong 

 to this tissue ; but this is rather apparent than real, and de- 

 pends upon the extent of its admixture with the next form of 

 fibrous or cellular tissue to be described, viz. the elastic. 

 (Plate XXXIX. fig. 7.) 



ELASTIC CELLULAR OR FIBROUS TISSUE. 



The elastic cellular or yellow fibrous tissue is distinguished 

 from the inelastic form by its branched filaments, the dia- 

 meter of which is unequal, its elasticity, its deeper colour, 

 and the absence of any appreciable effect on the addition of 

 acetic acid. (See Plate XL. Jig. 1.) 



Like the inelastic fibrous tissue, it rarely occurs in an 

 unmixed form, being mostly intermingled with it in variable 

 proportions: thus it is encountered in tendons, ligaments, 

 and, indeed, in all forms and conditions of the inelastic 



D D 2 



