AEEOLAR TISSUE. 



not only occur in the areolar tissue strictly so called, but form the chief 

 part of the tendons, ligaments, and other white fibrous connectiYe 

 tissues. They were 



long supposed to be Fig- 28. 



the only fibrous con- 

 stituent existing in 

 the areolar tissue, but 

 it is now well known 

 that fibres of another 

 kind are intermixed 

 with them ; these 

 agree in all characters 

 and are obviously 

 identical with the 

 fibres of the yellow 

 elastic tissue, and 

 have accordingly been 

 named the yellow or 

 elastic fibres, to dis- 

 tinguish them from 

 the white or waved 

 filaments above de- 

 scribed. 



In certain portions Fig. 2S. — Filaments of Areolar Tissue, in larger 

 of the areolar tissue, -^'d smaller bundles, as seen under a magnifving 

 as for instance in that ^«^'^^ *^^ ^^^ diameters. 

 which lies under the 



serous and mucous membranes of particular regions, the yellow or elastic 

 fibres are abundant and large, so tkat they cannot well be OTerlooked ; 

 but in other i)arts they 



are few in number, and Fi, 



small, and are then in a 

 great measure hidden by 

 the white filaments ; in 

 such cases, however, they 

 can alw.iys be rendered 

 conspicuous under the 

 microscope by means of 

 acetic acid, which causes 

 the white filaments to 

 swell up and become in- 

 distinct, whilst the elastic 

 fibres, not being affected 

 by that re-agent, come 

 then more clearly into 

 view (fig. 29). More- 

 over, they resist the 

 action of boiling alka- 

 line solutions of potash 

 and soda, of moderate 

 strength, which very 

 S])eedily destroy the rest 

 of the tissue. Under the 



29. 



Fig. 29. — Magnified View of Areolar Tissue 

 (from different parts) treated with Acetio 

 Acid. 



The white filaments are no longer seen, and the 

 yellow or elastic fibres with the nuclei come into view. 

 At c, a bundle of white fibres, which is swollen out by 

 the effect of the acid, and presents a number of con- 

 stricting bands as described in the text. 



