THE MUSCULAR SYSTEM. 253 



contain a larger quantity of fine elastic fibres in their con- 

 nective tissne, and in some places may even assume the structure 

 and dull-yellow aspect of the elastic membranes (vid. fig. 49), 

 and contain a close elastic network of the strongest kind. The 

 fascia are always of the tendinous character, where for some 

 mechanical purpose a tough unyielding structure is requisite. 

 They are of this kind, therefore : 1. At their origin from bones. 

 2. Where muscles arise from them; and they are of the nature 

 of aponeuroses. 3. Where tendons radiate into them and they 

 themselves act as terminal tendons. 4. Where thickened por- 

 tions of them supply the place of ligaments. On the other 

 hand they are more or less elastic, where they constitute a 

 firm envelope to the muscles, but, at the same time, one which 

 does not impede their changes in form. This is their character, 

 especially in the middle of the limbs. 



[The membranes interossece (forearm, leg, foramen ovale), 

 which are not usually reckoned among the fasciae, are not 

 apparently of the nature of ligaments of the bones, but rather 

 of intermuscular ligaments. The plantar and palmar apo- 

 neuroses serve, in part, as tendons for the smaller muscles of 

 the hand and foot, but chiefly as ligaments for the retention of 

 the flexor-tendons, in which respect they are analogous to the 

 liff. cruciatum carpi dorsale, &c. In them, even in the adult, 

 the entire course of development of the nuclear fibres (minute 

 elastic fibres), may be studied. Between the fasciculi of con- 

 nective tissue, straight series of 10 to 20 and more, thickly 

 placed, elliptical cells of 0'006 to O012'", with round nuclei, 

 and 2 to 6 minute opaque fat-granules, occasionally occur ; the 

 cells afterwards disappear, and the nuclei, which, on the addition 

 of acetic acid, appear a little yellowish, become more and more 

 elongated, and transformed into long, slender, straight, or 

 slightly-curved fibres, which are, finally, conjoined into long 

 nuclear fibres ; these fibres, however, upon the whole are 

 rare. The elongated nuclei are not always placed in a straight 

 line, one behind the other, but frequently in an oblique, and 

 in various other directions. In this way are produced serpentine 

 nuclear fibres, which, even when fully formed, are still sur- 

 rounded with isolated fat-granules, and lie as it were in vacant 

 spaces in the connective tissue. In this case, consequently, the 

 nuclear fibres are not formed from the nuclei of the cells, from 



