454 
PROFESSOR BEALE’S NEW OBSERVATIONS UPON THE 
connected with the very same fibre. If the muscle had gone on growing uniformly in 
all parts since the earliest period of its development, the nuclei would be separated from 
one another by equal distances, or by distances gradually but regularly increasing or 
diminishing from one extremity of the fibre towards the other. 
I think the irregular arrangement of the nuclei in these muscular fibres of the tongue 
is to be accounted for by their movements. Perhaps, of a collection of these nuclei 
close together, two may be moving upwards towards the narrow extremity of the muscle 
which is inserted into the connective tissue, while the third may be moving in the oppo- 
site direction. 
In some instances a “ fault ” is observed in the production of the muscular tissue, as if . 
the nucleus had bridged over a space and formed a thin layer or band of muscular 
tissue, which, when fully formed, was separated by a narrow space or interval from the 
rest of the muscle. See Plate XXII. fig. 12. 
In cases in which the nuclei are distributed at intervals throughout the muscular 
tissue, as in the large elementary fibres of the muscles of the frog, the formation of the 
contractile material gradually ceases as the elementary fibre attains its full size. When 
this point has been reached some of the nuclei gradually diminish in size, and their 
original seat is marked by a collection of granules. These granules are sometimes 
absorbed, and the seat of the original nucleus is marked by a short line which gradually 
tapers at the two extremities until it is lost. 
It is almost needless to say that no alteration produced by the different contractions 
of the muscle in different parts, would account for the position of the nuclei observed 
in the fine fibres of the papillae of the frog’s tongue. 
These views, it need scarcely be said, differ entirely from those generally entertained 
upon the development and formation of muscular tissue. They are supported by 
detailed observations made in all classes of animals, and in the same species at different 
periods of age. There are some facts in connexion with the changes occurring in disease 
which afford support to this view, which involves three positions. That in the nutrition 
of muscle the pabulum invariably becomes converted into germinal matter; that the 
latter undergoes change, and gradually becomes contractile tissue ; and that all the con- 
tractile material of muscle was once in the state of the material of which the nuclei or 
masses of germinal matter are composed. It is not deposited from the blood, nor pro- 
duced by the action of the nuclei at a distance, but it results from a change in the very 
matter of the nucleus itself. The manner in which this occurs has been already dis- 
cussed in the paper above referred to (Archives, No. XIV.). It was shown that the 
oval nucleus could be followed into a very fine band of contractile tissue or fibrilla 
(Plate XXII. fig. 13). We pass from the matter of the nucleus into very transparent 
imperfectly-formed tissue in which no transverse lines are perceptible, and from this 
into fully-developed contractile material in which the characteristic transverse markings 
are fully developed. 
