416 GENE-RAf? ANATOMY. 



them; that*the supposed transverse, twisted, 'and spiral fibres 

 &c., have never been seen, 'but only imagined, in support of 

 certain hypotheses in reference to muscular action; that in 

 short, the muscular fibre, differing essentially in' its organic 

 character, and in its vital phenomena, from the cellular and 

 nervous tissues, as well as that of the vessels, can not be as- 

 similated to these tissues. M.ascagni has revived and modified 

 one of those opinions, by considering the primitive cylinders 

 of the muscles'as formed of absorbent vessels filled with a con- 

 tractile glutinous substance in the living subject, constantly 

 renewed by the circulation. Nothing, however, demonstrates 

 this to be the case, or that the fibres are hollow; it is much 

 more probable that they are solid. *& pNfetfe . 



660. The muscles are enveloped by the cellular tissue 

 which forms membranes and sheaths for them: it is- the same 

 with regard to their bundles and the subdivisions of these 



O 



bundles; only, in proportion as the parts enveloped are less 

 voluminous, the cellular tissue forms envelops more slender 

 and soft. The fasciculi are enveloped and united together by 

 almost imperceptible layers of this tissue; in fact, the primitive 

 fibres are united together in each fasciculus, by prolongations 

 of its envelop, which, by their tenuity and softness, entirely 

 elude observation. The cellular envelops are perceptible either 

 by separating the bundles and the fasciculi from each other, or 

 by cutting the muscle transversely. 



Adipose* tissue is likewise found surrounding the muscles in 

 the intervals of their bundles, and sometimes even between 

 the fasciculi. 



661. The blood-vessels of the muscles, well described by 

 Albinus and Haller, and delineated by Prochaska and Mas- 

 cagni, are very numerous, less so, however, in the mucous 

 membrane. Their abundance is proportioned to the size of 

 the muscles; nevertheless, the interior muscles are more vas-- 

 cular than the exterior, and among the former some in particu- 

 lar are very much so. The veins, as in most of the parts, 

 possess a capacity superior to that of the arteries. They. all 

 communicate with the vessels of the tegumentary membranes, 

 especially in the immediate neighbourhood of the muscles: 



