OF THE ROUND LIGAMENT OF THE UTERUS. 
519 
of fusiform nucleated fibres, contained in a matrix of exceedingly coherent granular 
matter; these are well represented in fig. 3. The average breadth of on 6 of these 
fibres, at its dilated or nucleated part, is about of an inch ; their length can- 
not be ascertained with certainty, as it is impossible to estimate the degree of curtail- 
ment which they suffer in being separated from the granular matrix in which they lie 
imbedded. Their structure and size are about the same in every part of the uterus from 
which I have taken them, so that they are easily recognizable as the peculiar fibres 
of the unimpregnated uterus. Now comparing these fibres with those forming the 
walls of the impregnated one, at the full, or at a very advanced period of impregna- 
tion, it will be seen that these fibres are become greatly increased in size, deprived 
of nuclei, and more loosely connected together ; they lie in separate planes, which 
cross each other in various directions ; they are accompanied with vessels of various 
sizes, also with more or less fibro-cellular tissue. The size of these fibres is mode- 
rately uniform, but those near to the external surface are rather smaller than those 
more deeply seated. A fibre detached from the rest measured about 4 ^!^^ of inch 
in length and about aooo lh in breadth at its widest part ; for the breadth varies much 
in different parts of the same fibre, being alternately large and small ; at their extre- 
mities they taper off to a very fine point ; their colour is yellowish, and when minutely 
examined, they appear to be made up of very small irregular granules and extremely 
slender threads blended together without any definite arrangement (see fig. 4). Acted 
upon by acetic acid they give no indication whatever of being nucleated, therefore in 
this respect they differ from the common form of organic muscular fibre*. The two 
kinds of fibres, represented in figs. 3 and 4, were both drawn under the same magni- 
fying power, in order to show, by a comparison of their dimensions, that the increase 
which takes place in the individual fibres in these different states of the uterus, is 
quite sufficient to account for the amount of augmentation of the entire organ, with- 
out supposing, as some physiologists do, that organic muscular fibres, not present in 
the inactive state of the uterus, are absolutely formed during the various stages of its 
enlargement ; it also, besides being supported by the fact just stated, perfectly accords 
with the laws of development, and harmonizes with the changes which are going on 
simultaneously in the walls of the impregnated uterus and its contents ; the unim- 
pregnated uterus being, according to this notion, little more than an assemblage of 
embryonic nucleated fibres, wholly inactive, until after the reception of the ovum, 
when, being aroused by an appropriate stimulus, they are called into active operation, 
and become developed simultaneously and proportionally to the development of the 
foetus contained within it, so that when the one has arrived at a state requiring to be 
expelled, the other has acquired the utmost degree of fitness necessary to effect its 
expulsion. Now after the expulsion of the foetus, since, according to the laws of de- 
* Professor Kolliker has described the fibres both of the unimpregnated and impregnated uterus. The 
latter he has described and figured as having nuclei, which I have never been able to verify although I have 
examined these fibres with the greatest possible care. 
