246 GENERAL ANATOMY. 



the air vessels of the lungs ; it also lines some excretory ducts; 

 it forms the envelope of the cavernous body and that of the 

 spleen, and the yellow ligaments of the vertebras; it forms 

 moreover, in various animals, the posterior cervical ligament, 

 an abdominal tunic to the larger mammiferous animals, the 

 ligament which raises the nails of the cat, that which opens 

 bivalve shells; and in the greater number of the mammi- 

 ferous animals, it supplies the place of the little bones of the 

 tympanum. But it is especially in the middle coat of the arte- 

 ries, in the yellow ligaments, and in the ligamentum nuchae, 

 that its characters are most evident. It exists under two 

 principal forms; that of a canal, as in the parietes of the arte- 

 ries; and that of bundles, as in the yellow ligaments. 



This fibre is opaque, of a yellowish white, dry, firm, al- 

 ways arranged in parallel or very slightly oblique bundles, 

 never crossing each other, nor united by the celluar tissue, 

 and very easy to divide. It is extremely elastic, and in some 

 places it may be stretched twice its length; and afterwards it 

 forcibly recoils on itself, resuming its former condition. Its 

 strength in the living body is less than that of the muscular 

 tissue, but is stronger than the latter in the cadaver. In both 

 these states it is much less than that of the ligamentous tissue, 

 which it is almost impossible to extend. It is more tenacious 

 where it exists in bundles, and more brittle in the vessels. 



The elastic tissue contains nearly one half of its weight of 

 water; when it has lost its moisture by disseccation, it acquires 

 a horny appearance, a dark yellow colour, and becomes brittle 

 and diaphanous like horn. If plunged at this time in water, 

 it absorbs with avidity, and assumes its weight, aspect, and 

 former elasticity. It resists maceration for a long time, and 

 the cellular tissue does not become apparent in its structure. 

 The action of fire crisps it but little, and leaves behind very 

 little charcoal. Decoction scarcely crisps it, and extracts from 

 it a small quantity of gelatine, but never melts it, and this 

 operation does not destroy its elasticity. Acids render it 

 but little horny and do not make it transparent; it resists their 

 action for a long time, or experiences no effect at all. Diluted 



