The question is important, for unless we consider, with Haller, that the proper tissue of the tube resembles the cavernous body of the penis and clitoris, and that, as some have supposed, the tube, when filled with blood, is capable of erection, for which conjecture there appears to be no good foundation, it is impossible, in the absence of a contractile fibrous coat, to explain those movements of the oviduct, which must necessarily occur whenever the abdominal orifice is applied to the surface of the ovary — or that peris taltic action of the tube, witnessed by Bi schoff' in the Guinea-pig, by means of which the ova are carried backwards and forwards within the canal. See p. 611.
With a view of resolving the doubts raised by these conflicting statements, I have micro scopically examined the fibrous coat of the oviduct in the human subject at different pe riods of life, as well as in several genera of mammalia, and especially in Simia, Bos, Cer vus, and Delphinus. With regard to these latter examples, I find the evidence of the presence of a smooth muscular layer, consti tuting the middle coat of the oviduct, more or less decisive in different genera, but the existence of such a coat was most satisfac torily determined in Delphinus phocmna (preg nant). Here not only were the smooth muscular fibres, collected into long bundles, easily distinguished, but they were still more distinctly shown at the broken extremities of the latter, which exhibited the characteristic fusiforrn terminations of the individual fibre in such a manner as to leave no doubt as to the muscular nature of the tissue forming the principal portion of this coat, which contained besides an abundance of nuclear elements and common fibres of connective tissue.
With regard to the human subject, it ap pears to me that the assertion that the middle coat of the oviduct contains only fibrous tis sue, may have been based upon the examina tion of specimens taken from females advanced in life ; for, applied to such specimens, the statement is generally true, but in younger subjects, and when the proper reagents have been used, I have experienced no difficulty in finding more or less satisfactory evidence of the presence of smooth muscular fibres, provided only that a sufficiently high power, and the mode of illumination suitable to the discrimination of such tissues, were em ployed.
It must be observed, however, that the condition of this tissue is very variable. In
some subjects, the greater portion appears to consist of nuclear elements which here and there are seen intermixed with fusiform fibres of greater or less length. In other instances, the tissue is more distinctly fibrillar, the fibres beim, collected in bundles consisting of flattened filaments with distinct fusiform ter minations intermixed with bundles of white fibrous tissue ; while in some, and, I believe, generally in older subjects, the latter form of fibre, as just stated, abounds, and appears to constitute the principal portion of the middle coat of the tube.
The arrangement of the fibres constituting this coat is chiefly in the direction of the axis of the tube. This, indeed, appears to be entirely so at the surface; but deeper towards the central canal, nutnerous flat bundles cross ing the former at right angles are encoun tered, and these become more abundant still nearer to the mucous membrane, although, so far as I have been able to trace them, they do not constitute so distinct and separate a layer RS the outer longitudinal stratum.
The general condition of the lining mem brane of the tube, and its peculiar arrange ment, having been already described, it is only needful here to explain the composition and texture of this coat. This membrane, although commonly regarded as a mucous membrane, contains neither discoverable glands nor villi. It is composed of a very delicate pink or white soft layer, consisting of undeveloped connective tissue, mixed with numerous fusiform formative cells.
This thin layer is united to the fibrous coat by a small quantity of submucous tissue, which is also found lying between the folds of membrane forming the plicm, or ridges, and serving to connect together the two layers of which they are composed.
Covering this coat upon its inner surface is a thin layer of long cylindrical epithelial cells of a form peculiar to the Fallopian tube, of which Ilenle has given a minute account.# These, which are conical or filiform, are fur nished with an oval flattened nucleus, and have at their broad, unattached end a dis tinct row of cilia. These cells may be traced through the entire length of the tube, from the uterus to the free border of the fimbrim, where they gradually diminish in size, and, at the point of junction with the peritoneum, acquire the flattened form of the cells of pavement epithelium.