MUSCLE. 345 



with blood vessels: the larger vessels are contained in the 

 cellular tissue separating the fascicles or lacerti of the muscles, 

 and which serves to support and to conduct them; the 

 smaller vessels or capillaries are not encircled by cellular 

 tissue, but penetrate between the fibres, forming numerous 

 capillary loops and meshes, having their long axes disposed in 

 the direction of the length of the fibres. This arrangement 

 of the capillaries is shown in Plate XLI.jfy. 4. 



Much of the colour of a muscle arises from the blood 

 enclosed in the vessels, but not all, a portion of it being con- 

 tained in the muscular fibres themselves. 



It is evident that the contraction of the fibres exercises 

 much influence upon the capillary circulation, reducing the 

 calibre of the capillaries to such an extent as that the blood 

 corpuscles can pass through them only in an elongated form. 



In the course of the larger vessels, imbedded in the inter- 

 fascicular cellular tissue, fat corpuscles are often abundantly 

 distributed, as represented in Plate XLI. Jig. 1. 



Nerves of Muscles. Muscles are also abundantly supplied 

 with nerves, principally those of locomotion. Burdach has 

 figured and described the nerves in muscles as forming loops, 

 which either join other neighbouring loops or else return into 

 themselves. The figure and description given by Burdach 

 have been adopted by almost all succeeding anatomists ; not- 

 withstanding which, I would observe, that I have never seen 

 the nerves terminating in muscle in the manner indicated ; 

 not, however, that I doubt the fact of their doing so, because 

 such a mode of termination is common to nerves ; but would 

 simply infer from this, that the loop-like arrangement is 

 neither very general nor very obvious. 



According, then, to the latest physiologists, nerves, strictly 

 speaking, really have no termination whatever in muscles : 

 an opinion the accuracy of which is more than doubtful. 



I find that the nerves, after branching in a dichotomous 

 manner, have a real termination, and that from time to time 

 certain tubules leave the main trunks, and end in the form- 

 ation of elongated and ganglioniform organs situated between 

 the fibres of muscle. (See Plate XLI. Jig. 4.) 



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