TO THE ELEMENTAET EIBEES OF STEIPED MHSCLE. 
891 
agree as to the existence of free ends. The former maintains that these are situated 
beneath the sarcolemma, and are connected with peculiar organs; the latter, that the 
free ends he upon the surface of the sarcolemma. Kollikek has failed to demonstrate 
the special organs described by Kuhne. Both observers agree that the muscular fibre 
receives but a limited supply of nerves, and that the supply is limited to one part of 
the muscle. 
As these observers have worked upon the muscles of the frog, I shall restrict myself 
entirely to the consideration of the distribution of the nerves to the muscles of this 
animal, and mainly to the particular muscle which these and most German observers 
have studied, viz. the thin pectoral muscle. 
In many of KtiHisrE’s drawings a pale band as broad as (or broader than) the dark- 
bordered fibre is represented in continuity with it. The outlines of this band are irre- 
gular ; and in some places it is much wider than in others. This band is five or six 
times as wide as many fine nerve-fibres which I have seen ; and it will be shown that a 
fibre of the width of these pale fibres in the tissues of the frog generally, is a long 
distance from its finest divisions. The same observer makes the nerves of insects termi- 
nate in a collection of granular matter within the sarcolemma. 
1. The Distribution of Dark-bordered Fibres not so limited as generally supposed. 
With regard to the distribution of the dark-bordered fibres to voluntary muscle, I 
would remark 
That, although some muscles appear to be very sparingly supplied with dark-bordered 
nerves, the fibres of certain muscles (for example, the inferior muscle of the eye of the 
frog) are crossed by bundles composed of two or more fibres at intervals of about the 
fiftieth of an inch *. The distribution of nerve-fibres to the pectoral muscle is by no 
means so limited as would appear from cursory examination. It is clear that many 
branches, resulting from the division and subdivision of some of the large dark-bordered 
fibres, supply the elementary fibres near the centre of the muscle ; and to some muscular 
fibres four or five of the branches resulting from the subdivision appear to be distributed. 
These branches divide on the surface of the elementary muscular fibres, but their sub- 
divisions gradually become too fine to be followed. Some branches divide and subdivide 
into very fine fibres, which are lost amongst the connective tissue upon and between the 
muscular fibres. But it must not be supposed that all the nerve-fibres of the bundle 
are arranged thus ; for many pursue a much longer course. Bundles composed of two 
or three dark-bordered fibres leave the large trunk and pursue a long course obliquely 
across the surface of the muscle. The fibres of each trunk divide and subdivide ; and 
many of the branches which result reach almost to the extremities of some of the ele- 
mentary muscular fibres. Many pass between the muscular fibres, and, after pursuing a 
* The muscular fibres of the diaphragm of the mouse are crossed by bundles of dark-bordered fibres at short 
intervals along their whole length, and nerve-fibres may be seen at the points where they are inserted into 
the central tendon. 
6 p2 
