Under ordinary circumstances, and when the organs are healthy, the canal of the Fal lopian tube contains only a small quantity of slightly viscid mucus. But when death has taken place during a menstrual period, the fluid is found to he replaced by blood which is usually of a dark colour, and uneoagulated. This fluid presents, under the microscope, the characters of ordinary blood, with which numerous epithelial scales, derived from the walls of the containing tube, are intermixed.
Blood vessels and nerves. — M. Richard is, so far as I am aware, the only author who has been at the pains to examine and de scribe with anything like minuteness the pre cise arrangement and di,tribution of the blood-vessels supplying the Fallopiaa tube. The following is his account, the general accuracy of which I have verified by frequent injections of these vessels.
" There exists always a special artery for the tube. Springing from one of the nume rous branches of the uterine artery, near the angle of the uterus, this vessel takes a direc tion from within outwards, from the com mencement of the oviduct, as far as the neighbourhood of the pavilion, describing, like the tube itself, a curve, the concavity of which looks towards the side of the ovary. The artery, which is lodged in the substance of the anesentery of the tube, takes a slightly sinuous course, parallel with the oviduct, and at the distance of one or two finger breadths from it. Situated in the middle of the fila mentous cellular tissue, which exists between the two layers of peritoneum, it passes con stantly behind the organ of Rosenmiiller ; so constantly, that keeping this relation in mind, one could immediately, if the neighbouring organs were removed, distinguish the anterior from the posterior face of the lesser wing of the broad ligament. The artery is accom panied by the two veins of the tube, and sur rounded by very delicate nervous filaments.
" The branches furnished by this artery are lateral as well as terminal. The lateral branches are generally three in number. The first enters the inner third of the body of the tube, at a distance of three or four centi metres from the uterus ; the second supplies the middle, and the third the outermost ex tremity of the oviduct. These three branches before arriving at the tube bifurcate, the twigs resulting from which bifurcations are directed the one to the right and the other to the left to inosculate with each other. From this
results a series of arches furnishing branches to every portion of the body of the tube. The innermost bifurcating branch anastomoses with a branch derived from the proper artery of the uterus, so that a well-marked analogy between the distribution of the tubal artery and that of the niesentery is here observable. The terminal division is distributed to the pavilion. It separates into a greater or less number of tortuous branches, each of which goes to supply a fringe of the pavilion ; the tubo-ovarian fringes also receive each a twig of the tubal artery. Sometimes, however, a small branch of the utero-ovarian artery, froin which it is detached opposite to the external extremity of the ovary, establishes one of the anastomoses between the uterine and the utero-ovarian vessel. From the concavity of the tubal artery very small branches pro ceed to the organ of Rosenmiiller, and to the neighbouring cellular tissue." But no adequate notion can be formed of the extreme richness of supply of vessels to this and the neighbouring organs until, after a successful minute injection, the parts have been dried and preserved in b dsam. Nume rous vessels which the opacity of the parts had previously concealed are then brought into view. They are seen running parallel with the surface of the tube, and mostly con verging towards the fimbrize, upon and in the substance of which they lie as thickly as the pile of velvet, previously to their dis persion into their final capillary terminations. It was probably this exuberance of vascular supply that led some former observers to imagine that the tube possessed an erectile tissue, a structure of which the most minute injections do not suffice to exhibit a trace.
The veins, which follow the same course as the arteries of the tube, frequently an astomose with one another by transverse branches, which serve to connect too-ether the tw o principal trunks. These gather the returning blood and carry it into the plexus of uterine veins placed along the sides of the uterus.
The lyniphatics of the tube have the same common source as those supplying the rest of the internal generative organ.
The nerves, which are very slender, follow the course of the arteries. They are de rived, according to Dr. Snow Beck, from the hypogastric and aortic plexuses.