JOURNAL OF MICROSCOPICAL SCIENCE. 
DESCRIPTION OF PLATE XIII, 
Illustrating Lionel S. Beale’s paper in the “ Proceedings ” on 
Further Observations in favour of the View that Nerve- 
fibres never end in Voluntary Muscle. 
Distribution of finest nucleated nerve-fibres to the very narrow elementary 
muscular fibres of the mylo-hyoid of the little green tree-froy (Hyla arborea), 
magnified 1700 diameters. Drawn on the block by the author. 
The elementary muscular fibres are marked g, 4, 7,4. &Isa very young 
one, slightly stretched; ¢ is a fully formed muscular fibre; , another 
stretched in its central part. The nuclei of these fibres exhibit some differ- 
ences in size and form. Nucleoli are distinct in all, and in the fibre marked 
g the nuclei, which were coloured by carmine, exhibit three different in- 
tensities of colour—the dark central spot, “nucleolus,” being most in- 
tensely coloured, as indicated by the shading in the drawing. 
a Is a nerve-fibre which was followed over more than twenty elementary 
muscular fibres from a dark-bordered fibre. One of the subdivisions of this 
fibre is seen at f, where it again runs with a very fine dark-bordered fibre 
(0). The dark-bordered fibre (0) was some distance higher up in the speci- 
men, but its place has been altered in order to avoid the necessity for a still 
larger drawing. Above 4 a nucleus of avery fine nerve-fibre is seen. Such 
nuclei lie upon the surface of the muscular fibres, external to the sarco- 
lemma. The nucleus often appears as if it were within the sarcolemma (ce), 
but the fibres proceeding from each extremity render such a position impos- 
sible. The relation of these nerve-nuclei to the sarcolemma is seen at / in 
profile. , The nuclei, as well as the fibres for a certain distance, often adhere 
to the sarcolemma very firmly ; but in the thin mylo-hyoid muscle the course 
of the fibres over or under, but always ea/erzal, to the muscular fibres, may 
be readily traced if the muscular fibres be separated slightly from each other, 
as represented in the drawing. 
At d fine nerve-fibres accompanying the fine fibre continued from the 
dark-bordered fibre, as described in the ‘ Philosophical Transactions’ for 
1862, are represented. Such fibres are also seen at e and #- 
m,n, end o. Dark-bordered fibres, with nuclei near their distribution. 
m Would probably pass over sixty or seventy muscular fibres, and # over 
perhaps twenty, before it divided into fibres as fine as those seen at 4, e, 7, 0. 
p. A very fine capillary vessel with a nerve-fibre running close to it. 
g. A bundle composed of six very fine nerve-libres near their distribution. 
These fibres exhibit a very distinctly beaded appearance, which is also ob- 
served in many other fine fibres in different parts of the specimen. 
Traces of connective tissue are seen in all parts near the fine nerve-fibres 
and around the muscular fibres. Here and there some very fine conncctive- 
tissue-fibres, which were not altered by acetic acid, are represented. ‘These 
represent the remains of fine nerve-fibres, which existed in a state of func- 
tional activity at an earlier period. 
The drawing, with the exception of the position of the nerve-fibre (0) 
above mentioned, is an actual copy from nature. ‘The relative position of 
the muscular fibres, the form and general character of the so-called nuclei, 
and the position and size of the nerve-fibres and their nuclei, have been care- 
fully preserved. 
1 have traced the very fine nerve-fibres in so many instances from one 
trunk to another ramifying at a very considerable distance, that I cannot 
believe any true terminations or ends exist. 
