Dr. Beale^ on Sarcolemma, 
99 
are undoubtedly of the same nature — not^ as he has repre- 
sented them^ a nucleated structure, in which the nerve ends, 
situated beneath the sarcolemma. 
From what has already been said it will be inferred that 
I hold the opinion that many of the nuclei seen in connec- 
tion with the sarcolemma of striped muscle are really the 
nuclei of vessels and nerves ramifying upon its external 
surface. Not only so, but I have proved that these nuclei may 
be stripped off from the surface of the sarcolemma with the 
vessels and nerves to which they belong, leaving this 
membranous tube clear and almost destitute of any nuclei 
whatever. I have even stripped off' the layer in which the 
vessels and nerves ramify from the surface of the sarco- 
lemma, by forcing injection in the interval between. (See 
^Phil. Trans./ 1860, p. 616.) In other cases, however, the 
capillary vessels and nerves adhere so intimately to the sarco- 
lemma that they may be said to form part of its substance. 
0/ the 7iuclei of the sarcolemma. — Besides the three kinds 
of nuclei observed in connection with the embryonic muscle, 
and consisting of — (1) nuclei concerned in the develop- 
ment of the muscular tissue ; (2) nuclei taking part in the 
formation of vessels ; (fig. 3) those taking part in the pro- 
duction of nerves; there are in the fully formed muscle 
(4) nuclei imbedded in the substance of the sarcolemma; 
(5) nuclei in the connective tissue, upon its external surface, 
and continuous with it ; and, (fig. 6) nuclei upon the surface of 
the contractile tissue, just beneath the surface of the sarco- 
lemma. In order to ascertain the nature and mode of origin 
of the nuclei which are not connected with muscles, nerves, 
or vessels, it is necessary to consider more particularly 
the mode of origin of the transparent membranous sarco- 
lemma itself. 
It has been already stated that sarcolemma is imper- 
ceptible in young muscles, distinct but thin in fully formed 
muscles, thick and comparatively firm in old muscles. Now, 
it is quite certain that the sarcolemma does not result 
from changes taking place in an expansion of flattened cells 
covering the surface of the muscle — an undoubted mode 
of origin of some delicate membranous structures — for no 
such cells are to be demonstrated during the development 
of the muscle in any case. Next, it must be borne in mind 
that the apparent smoothness of the external surface of the 
sarcolemma is due to the action of the fluids in which it is 
usually immersed for the purpose of examination. If, how- 
ever, the most smooth sarcolemma be carefully preserved 
in viscid media, readily miscible with water, as syrup or 
