902 
PEOFESSOE BEALE ON THE DISTEIBTJTION OE NEEVES 
tlie commencement of that portion of the nerve-fihre which influences the muscle and 
corresponds with the fine fibres composing the network in the bladder of the frog (Plate 
XLI. fig. 6). From what I have seen of the distribution of nerves to tissues generally, I 
feel convinced that the really important part of the peripheral nerve-fibres, by which the 
various tissues under the control of the nervous system are influenced, really only com- 
mences at the point where the white substance seems to cease. Beyond this point, and 
continuous with the dark-bordered fibres, there is a most extensive system of fine fibres 
with which nuclei are connected. The fibres are compound, and the arrangement of 
the bands is such as to produce the appearance of a network, in the meshes of which 
the active elements of the tissue are situated. 
The relation of Nerve-fibres to the Connective Tissue of Muscle. 
I have shown that the network of delicate compound nerve-fibres on the surface of the 
muscular fibres is continuous with certain fibres and nuclei which seem to belong to the 
connective tissue around the muscular fibres (p. 892). This connective tissue is thicker 
in old animals than in young ones, and may be regarded as constituted mainly of the 
remains of a structure which was active at an earlier period of life. These remarks do 
not in any way apply to the fascia of a muscle, but only to the indefinite connective tissue 
beneath it, and in close contact with the sarcolemma and between the muscular fibres. 
Many of the fibres delineated by Kuhne in fig. 15, plate 4 of his memoir, and termed 
by him fibres of connective tissue, are made exactly to resemble the pale nerve-fibres ; 
and their nuclei are of the same size. The fibres of ‘ connective tissue ’ (1) which leave 
the sides of the dark-bordered fibres represented in his drawings do not accord at all with 
appearances I have seen, which are much more positive. Kuhne gives a nucleus lying 
outside the white substance with indefinite fibrous tissue proceeding from it. In my 
specimens such a nucleus is seen continuous with definite fibres in the ‘ matrix ’ external 
to the white substance (Plates XLIII. & XLIV. figs. 17, 28, & 31). From the nucleus 
definite fibres can often be traced in opposite directions ; and on one side of it three or 
fom' fine fibres may often be demonstrated (fig. 31). It is unnecessary here to repeat the 
various arguments that have been adduced in favour of the view that these fibres are 
veritable nerve-fibres, and not mere connective tissue. This important question is 
decided by some preparations I have made showing the distribution of the nerves m the 
bladder of the frog* ; and I am sure if will be admitted, at least by those who have seen 
* Kollikee, speaking of the distribution of tbe nerves, says, “ The same mode of termination as in the 
heart (very fine pointed extremities) prevails in the non-striated muscular tissue of the pharynx and bladder 
of the frog.” I have fully investigated the arrangement of the nerve-fibres in the bladder of the frog, and 
have given drawings of the appearances I have observed in this paper, and also in No. XII. of the ‘Archives 
of Medicine.’ I can follow the finest nucleated fibres for long distances ; but they always pass to other fibres, 
and never terminate in any ends that I can discover. In many situations there is a network with compara- 
tively small meshes, as represented in Plate XLI. fig. 6. Amongst the delicate striped fibres of the auricle of 
the heart of the frog I have also seen bundles of very fine fibres forming networks with large meshes ; but 
I have never seen ends, and feel sure that free ends do not exist in these tissues. 
