48 



MANUAL OF PHYSIOLOGY. 



all their reproductive energy to the formation of this fibrillated 

 substance which ultimately forms the great bulk of the tissue, 

 while the cells become gradually and proportionately fewer in 

 number. In this case only sufficient of the mucous substances 

 generally remains to cement the fibrils together into bundles. A 



FIG. 27. 



FIG. 28. 



FIG. 27. Coarse (a) and fine (6) yellow elastic fibres after treatment with 

 strong acetic acid. (Cadiat.) 



FIG. 28. Elastic membrane from inner coat of aorta, and, below, mesh- 

 work of elastic fibres from a yellow ligament. (Cadiat.) 



few of the cells, however, remain between the bundles of fibrils 

 to preside over the nutrition of the tissue. Thus is formed the 

 non-elastic or white fibrous tissue of tendon. 



As a general rule these fibrils are easily affected by chemical 

 re-agents. Weak acids cause them to swell up and become indis- 

 tinct. Baryta water affects the cement and renders them easily 

 separable. They swell and dissolve in boiling water, yielding gel- 

 atine, which forms a jelly on cooling. 



