250 
MR. SAVORY ON THE DEVELOPMENT OF 
fibre, generally at an equal distance from either margin. They are large and oval, 
with their long axis in the direction of the fibre. Between these, widely scattered 
clusters of granules are seen — the remains of those which have perished, and which 
soon disappear. The striae, although faintly and delicately marked, are sufficiently 
obvious, especially towards the circumference. 
The fibre now commences to increase in size, and its development is continued by 
means of the surrounding cytoblasts, which are very numerous amongst the fibres. 
These may be seen to become attached to its exterior, and then invested by a layer of 
the surrounding blastema. Thus, as it were, nodes are formed at intervals on the 
surface of the fibre. In some specimens the adherent nuclei may be seen attached 
to the fibre at very regular distances, but in many cases no such uniformity can be 
detected. Generally, however, the nuclei are so near to each other, that the invest- 
ing material of one, as it spreads, becomes blended with that of its neighbour, and 
so a continuous layer of fresh material of greater or less extent is added to the ex- 
terior of the fibre. This is at first clear and pellucid, like the original border of the 
fibre when first formed, and presents a striking contrast to the present substance of 
the fibre. It is at this period readily detached by a little rough manipulation, but it 
soon becomes intimately connected and indefinitely blended with the exterior of the 
fibre. The striae and other characters of the adjacent portions of the fibre are soon 
acquired ; the nuclei at the same time gradually sink into the substance of the fibre, 
and an ill-defined elevation, which soon disappears, is all that remains. (See Plate XI. 
fig. 1 1, a, 6 & c.)* 
Sometimes these changes occur around a single nucleus which is isolated from any 
other. More frequently, the blastema surrounding many nuclei, attached at short 
intervals along the lengths of the fibre, becomes blended into a uniform layer ; and 
this is often of such considerable extent, that it appears as a regular band lying along 
the whole length of the fibre. With a little dissection these bands may generally be 
detached, and they then appear as small accessory fibres, lying by the sides of the 
others. (See Plate XI. fig. 13 b). 
Between the extreme conditions all intermediate variations may be found ; some- 
times the investments of different nuclei adhere more firmly to the exteiior of the 
fibre than to each other, but it more frequently happens that as they coalesce they 
are more readily separated together from the fibre than from each other. 
If a portion of muscular tissue be examined at the period when the fibres are in- 
creasing by the addition of fresh nuclei, there will be seen in the field, besides a num- 
ber of free nuclei, many nuclei floating about invested by blastema, and having the 
appearance of caudate cells. These are nuclei which have adhered to the fibre and 
become coated, and afterwards detached by violence. 
* I think that some sketches published by Virchow in his ‘ Archiv fiir Pathologische Anatomie und Phy- 
siologic und fiir Klinische Mediciii,’ Siebenten Bandes, Erstes Heft, must have been drawn from muscular fibres 
in this stage of their development. 
