BARLOW ON TENDINOUS STRUCTURES. 
257 
find in the extremities, more special modifications of the same 
tissue in the characters of tendons and ligaments, uniting bone to 
bone, or muscle to bone, and so anatomically arranged as to asso- 
ciate them in a manner the most advantageous for symmetrical 
appearance, and for purposes of strength, whether actively or pas- 
sively required. 
In conformity with the carrying out of these important objects, 
the arrangement of tendinous tissue in the vicinity of the shoulder 
joint is, as Mr. Mayhew observes, such as to obviate, so far as may 
be, muscular substance from the effects of traction, and to fulfil the 
purposes of ligaments to the articulation : yet, in the description 
which he has given of the anatomical distribution of this tendinous 
tissue, there cannot be any thing “ hitherto unobserved” by the 
anatomist. In many of the muscles connecting the scapula to the 
humerus, as well as in many muscles of the fore and hind ex- 
tremities and elsewhere, the tendinous structure will be found 
chiefly arranged in the three following ways : — First, As in the 
antea and postea spinatus, or subscapularis, &c., there is a dense 
expansion covering a greater part of the muscles externally, and 
frequently entering more or less into the muscular substance. 
This tendinous tissue proceeds from the circumferent points of the 
origin of the muscles to be united with their tendons of insertion. 
Second, In the inner substance of the muscles there are sets of 
tendinous fibres uniting with muscular ones, of which the tendi- 
nous are the continuations. Third, Other sets of fibres which, as 
Mr. Mayhew states, are found passing in “ direct unbroken” lines 
along the muscles from bone to bone, to which they are attached, 
and forming the “ ligaments of the joints.” Although this descrip- 
tion of the tendinous fibres may not be given in veterinary ana- 
tomical works, and although it is the one I am in the habit of 
adopting, still I should have hesitated to have concluded that the 
“ structures” and arrangement had “ been hitherto unobserved” by 
others. 
In attaching deserved importance to the last-mentioned arrange- 
ment, I think the author of the essay attaches too little to the 
former. We cannot doubt that tendon passing direct from bone 
to bone does, in virtue of its physical power, contribute in a 
most material degree towards preserving from fatigue, stress, or 
injury, muscular fibre passing in the same direction ; but we are not 
to overlook the importance of the dense external sheath in not only 
promoting the same object, but in preserving the muscle and tendon 
internally in the most advantageous position for executing their 
functions. Nor are we to forget that even voluntary muscles pos- 
sess a certain degree of contractile power, the exercise of which 
is continual, and does not induce fatigue. Tn other words, they 
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