102 
Dr. Beale, on Sarcolemma. 
would appear that nuclei found in intimate relation with the 
tissue of the sarcolemma are nuclei descended from the very 
same nuclei as those from which the muscular tissue itself has 
been produced. And I conceive that the different conditions 
under which the former nuclei have been placed is quite sufficient 
to explain why_, in this case, a tissue of very simple character, 
and without any special endowments, results. Moreover, it 
is quite possible that as the muscle advances in age the oldest 
portion of the contractile tissue degenerates, and the material 
which was incapable of absorption might thus go to increase 
the thickness of the sarcolemma from within, and a few of 
the nuclei, escaping destruction, would at length be imbedded 
in the substance of the sarcolemma, thus thickened by the 
addition of a simple form of connective tissue. 
It seems to me that the above explanations fully account 
for the formation of all the nuclei which have been demon- 
strated to exist in connection with the sarcolemma. 
The relation of sarcolemma to the vessels, nerves, and 
contractile tissue of muscle. — But at the present time the 
structure, origin, and mode of formation of the sarcolemma are 
of special interest with reference to the mode of distribution 
of nerves to striped muscular fibre. As is well known, the 
conclusions I have arrived at are at variance with those of 
Continental anatomists, not only upon the question as to 
whether the nerves terminate in free ends or form complete 
circuits, but also with reference to the position of the nerve- 
fibres with respect to the sarcolemma ; the general opinion 
now entertained being that the nerves actually perforate the 
sarcolemma and come into contact with the contractile 
tissue. The existence of such an arrangement is, without 
doubt, supported by the investigations of a great number of 
observers. The question is, however, one of such extreme 
delicacy, and for its elucidation requires such great care in 
the preparation of specimens, that many of the conclusions 
arrived at may result from misinterpretation of the appear- 
ances observed. I would, however, remark that many of the 
appearances delineated are at variance with what I have my- 
self seen and have demonstrated to others, while the conclu- 
sions are so utterly incompatible with collateral evidence, 
that many independent observers refuse to accept them upon 
this last ground alone. 
/ 
