nervus trigeminus; the same was in cases of Cassirer and Schiff (1st observ. 2nd, 7th). According to the membrane theory the degeneration of the spinal root of the fifth nerve is a necessary sequel of the disconnection of the sensitive portion of the trigeminus from its center, Gangl. Gasseri, and is thus analogous to the similar process in spinal nerves. The cause of such a disconnection is most probably an inflammatory process in the cranial membranes, i. e., some form of meningitis. A similar view on the cause of the degeneration of the spinal root, which Oppenheim observed in one case of undoubted syphilis of the central nervous system, was expressed by him in one short article, published in 1894 and already mentioned on page 267 of the July issue. * He speaks there about the atrophy of the Gasserian ganglion occasioned together with the atrophy of the spinal root of the fifth nerve which observation confirms in his opinion the theory of Marie -that in tabes the ganglia become affected primarily, the departing roots, however, secondarily. Besides the atrophy of the spinal root of the fifth pair in syphilis of the nervous system, Oppenheim observed also the atrophy of the solitary bundle (Solitärbündel) and such changes, says Oppenheim, we must explain on the ground of the newest views in such a way that the degeneration of the intrabulbar roots is a secondary process and probably only a sequel of the basal meningitis. By the same reason similar discoveries in tabes dorsalis can have an entirely new explanation. (,,Auf Grund der neueren Anschauungen müssen wir jedoch annehmen, dass diese Degeneration der intrabulbären Wurzeln eine secundäre und vielleicht nur die Folge einer Basalen Meningitis sei. Damit tritt auch ihre Beziehung zur analogen Befunden by Tabes in ein anderes Licht."-Prof. Oppenheim.)

According to the membrane theory the degeneration of the intrabulbar roots is a secondary process-a result of their

*Prof. Oppenheim: Zur path. Anatomie der Tabes dorsalis (Berliner Klin. Wochenschr, pp. 689-691).

disconnection from the center; for the sensory portion of the trifacial nerve this center is the Gasserian ganglion. The affection of the latter, as it was described by Oppenheim, is also the result of the secondary degeneration, viz., retrograde. Besides this, this ganglion is invested by a capsule of the cranial membranes. It is clear that the inflammatory process in cerebral tabes may be located in this capsule, then extend over the ganglion per continuitatem and later on produce the atrophy of the roots. In both cases the cause of the atrophy has to be looked for in the changes of the membranes and it can be readily explained by them.

Regarding the motor portion of the nervus trigeminus, it also must become degenerated and atrophied and as a result we shall get the affection of the masticatory muscles, which was described, according to Leyden and Goldscheider, by Peterson and Schulz. The central portion of the motor root, like the nuclei themselves, may or may not be affected. All symptoms on the part of the fifth pair, clinical as well as anatomical, observed in tabes dorsalis may be, in my opinion, explained thus very well by the membrane theory, namely that the process arises in the cerebral membranes and affects the roots of the trifacial nerve.

The lesions of the sixth pair, of the nervus abducens, in tabes dorsalis will be also comprehensible if we will accept as the starting point the cranial membranes. While compressing and disconnecting the root of this nerve at the place of its exit from the brain, they will produce degeneration of this nerve, peripheral in character, and later on its atrophy with paralysis of the musculus rectus internus, while the nucleus of this nerve may become affected or not, according to the intensity and duration of the morbid process.

The affection of the nervus abducens, and the parts in. nervated by this nerve, is a very common occurrence in tabes dorsalis, one of the most frequent occurrences in this disease, while the affection of its nucleus, as a result of the retrograde degeneration with the affection at the same time of the

muscle is very seldom met with. Our propositions are amply confirmed by other facts shown in the literature. I will quote only Leyden, Goldscheider and Strümpell: "Tabetic ocular palsies are partly of peripheral, partly of nuclear origin. Mostly they are of peripheral origin, because in several cases the ocular nerves were found changed, while the nuclei were found completely normal." (,,Die tabischen Augenmuskellähmungen sind theils peripherer Art, theils vom Kern ausgehend (nucleär). Vorwiegend handelt es sich wohl um peripherische Läsionen, da in mehreren Fällen die Augenmuskelnerven alterirt, die Kerne aber frei gefunden wurden" (p. 533 of the 10th vol. of Nothnagel's specielle Path. u. Therap., first ed.).

Prof. Strümpell on p. 793 of his text-book (3rd American ed.) says: "It is very probable that the temporary ocular paralyses in tabetic patients depend on the changes in the peripheral nerves of the ocular muscles."

Both these quotations correspond entirely to the membrane theory, according to which the lesions of the sixth pair in tabes are referred to the disconnection of the trunk of this nerve from the center by the chronic inflamed or otherwise changed membrane.

(To be concluded.)

In the preceding portion of this contribution (July number) the following corrections should be noted, viz.:

Page 260, line 5, read: this disease starts not in the posterior roots. Page 270, line 3d, below: add Strümpell.

Page 277, line 2d, below: take out "in" after the word "Mariè."

LECTURES ON GYNECOLOGY.-By FRANKLIN

H. MARTIN, M. D., Professor of Gynecology, Post
Graduate Medical School, Chicago.

THE PERINEUM.

The female perineum constitutes the point of union and decussation of a series of muscles which form, with several layers of fascia, the main support of the floor of the pelvis. It is an error to designate the mass of tissue constituted by these muscles and fascia as a distinct body.

The muscles with which we have to interest ourselves specially are:

First, the sphincter vagina, which has a central attachment of a tendinous nature in the recto-vaginal space, and which is continuous laterally with the sphincter ani and the transversus perinei muscles. It passes forward on each side of the entrance to the vagina, to be inserted into the corpus cavernosum clitoridis, the more transverse fibers radiating to be inserted into the triangular ligament and ramus of the pubis.

Second-The transversus perinei, which arise on each side from the ramus of the ischium and become inserted in the sides of the sphincter vagina and decussate between the vulva and the anus.

Third-The levator ani, which is a thin plane of muscular fibers situated in the side of the vagina. This muscle arises from the inner surface of the os pubis near the pubic arch, from the upper border of the spine of the ischium and between those points from the tendinous arch which occupies the line of division of the pelvic fascia into the obturator fascia and recto-vesical fascia. Its fibers descend to be inserted into its fellow on the opposite side of the vulva and the

anus, into the side of the rectum and behind the rectum, into its fellow of the opposite side and the side of the extremity of the coccyx.

The fibers from these several muscles passing around the outlet of the vagina and the anus, constitute the sphincter vaginæ. And all these muscles with their fibers decussating and joining between the lower rectum and the vulva, together with several layers of fascia, constitute what is known as the perineal body.

anus.

The Action of the Muscles Constituting the Perineum. — A careful study of these muscles soon makes apparent the effect that each has upon the perineum, the vulva and the The sphincter vaginæ, from its attachment forward to the ramus of the pubis, while encircling the vulva and by its contraction constricting its outlet, also from its bony attachment, has a tendency to draw the mouth of the vagina and the anus forward. The transversus perinei muscle from its bony attachment to the ramus of the ischium, has a tendency, when acting alone, to draw the perineum, vulva and anus to the corresponding side with its attachment. The two muscles acting in unison maintain the vulva and anus in the center of the floor of the pelvis and by contraction of its anterior portion elevates or draws the vulva and anus toward the symphysis pubis, while its posterior portion, which has its fixed attachment to the coccyx, in turn has a tendency to draw the anus posteriorly, or backwards toward the coccyx.

These various muscles, with their fibers, surrounding the vulva and the anus, constitute the sphincter muscles of those two tubes, and all these muscles, the transversus perinei, the levator ani, and the sphincter muscles, maintain the lower ends of those tubes in their proper relations with each other, and constitute the muscular floor of the pelvis.

The Effect of Injury on the Muscles of the Perineum.A destruction of the continuity of the fibers of the sphincter of the vagina obviously will cause a relaxation of the vaginal outlet. An injury or destruction of the transversus perinei