the primeval pig, and the mew of the pre-Adamitie kitten, those who with me look on Darwinism as a mere pleasant conceit of men besotted in the one-sided study of physical science, can, so far as philological conclusions are concerned, leave the conceit to shift for itself, being firmly convinced that whenever reason does show itself whether on the original appearance of man or at some after-stage of his development, it appears as a force altogether different from, and in some of its functions, as Professor Ferrier wisely maintained, essentially contradictory of, and antagonistic to, every kind and degree of mere sensation; and in this character brings forth language as the natural manifestation and organised body of itself.

Monday, 7th February 1876.

SIR WILLIAM THOMSON, President, in the Chair. The following Communications were read:

1. Note on Certain Formulæ in the Calculus of Operations. By Professor Stokes, Hon. F.R.S.E. (In a letter to Professor Tait.)

*

January 14th, 1876. "Formulæ like those you sent met are readily suggested by supposing the function operated on to be of the form Axa, or say, for shortness, xa, with the understanding that no transformations are to be made which are not equally valid for Axa.

The direct transformation may readily be effected by noticing, in the first instance, that any two operations of the form

Replacing the operations in the left hand member of the first formula by convertible operations, which will be separated by points, we find

2. A Further Contribution to the Placentation of the Cetacea

(Monodon Monoceros). By Professor Turner.

In the year 1871, I read before this Society a memoir on the Gravid Uterus of Orca gladiator, in which I discussed the placentation of the Cetacea. This memoir was published in the Transactions for that year. On the present occasion I purpose describing the placenta in a Cetacean genus in which it has not hitherto been examined.

In the month of December 1875 I received, through the intermediation of my friend Mr C. W. Peach, from Mr John Maclauchlan, the chief Librarian and Curator to the Free Library, Dundee, a cask containing the gravid uterus of a Narwhal (Monodon Monoceros), which had been procured by the captain of the Dundee whaling steamer "Erik." The uterus had been preserved in strong brine, and was in good condition for anatomical examination.

The uterus was two-horned, and contained a foetus 5 feet 5 inches long in the left cornu. The gravid horn measured 7 feet 4 inches along its great curvature; the non-gravid, 4 feet. The girth of the gravid horn, at its thickest part, was 4 feet 4 inches. The length of the corpus uteri was 1 foot; that of the vagina, 1 foot 8 inches. The os was occluded by an extremely viscid mucus.

The uterine cornua were opened into by a longitudinal incision along the greater curvatures. The uterine wall was comparatively thin, and the chorion was closely adherent to its mucous lining. By an incision through the chorion, along the greater curvature of the gravid horn, the sac of the amnion was opened into and the foetus exposed. The foetus lay with its back in relation to the greater curvature of the cornu, its belly to the lesser curvature, its head close to the corpus uteri; whilst its caudal end was directed to the narrow end of the horn, but did not reach to within two feet of the Fallopian tube. The tail was curved forwards under the hinder part of the ventral surface of the foetus. The pectoral flipper was directed backwards parallel to the long axis of the body. The umbilical cord was 3 feet long, spirally twisted, and bifurcating where it reached the sac of the allantois. The amnion formed an immense bag, which reached to 5 inches from the free end of the gravid horn of the chorion, but it did not extend into that part of

the chorion which occupied the non-gravid horn. The amnion was closely adherent to the greater part of the chorion in the gravid cornu; but that portion of the chorion which was attached to the mucosa lining the lesser curvature of the cornu, and which lay opposite the abdominal aspect of the foetus, was in relation to the wall of the sac of the allantois. The allantois formed a large funnel-shaped bag at the place of bifurcation of the cord. It was prolonged along the concavity of the chorion to within 2 inches of its free end in the gravid horn, and to within 9 inches of the free end of the prolongation of the chorion into the non-gravid horn. The length of the sac of the allantois was therefore much greater than that of the amnion, though its capacity was much less. The allantois was prolonged as a slender tubular urachus into the umbilical cord, which also contained two large arteries and two veins. The amnion investing the cord had numerous brownish corpuscles, resembling those I have described in Orca gladiator, projecting from it; and similar corpuscles were scattered over that part of the amnion which was in apposition with the wall of the sac of the allantois, and a few were seen on the amnion beyond the border of the allantois. In addition to these brown corpuscles, numerous other bodies of a dull white appearance were found. Sometimes these were slender rods, from 1th to 16th inch long, arranged end to end like the links of a chain, at other times they were globular, like minute shot. The rods were most numerous on the abdominal half of the cord, whilst the globules were most numerous at and near its bifurcation. The surface of the amuion adjacent to the cord had a few of these globules scattered over it. These white bodies were covered by the smooth amnion, which with a little care could be stripped off as a distinct pellucid membrane. They consisted of crowds of squamous epithelial cells, so that in structure they resembled the whitish bodies which are 80 abundantly developed in connection with the amnion of the cow. Between 3 and 4 inches of the abdominal end of the cord was covered with cuticle, which had the purplish-grey colour of the cuticular investment of the adjacent surface of the wall of the belly.

The two uterine cornua became continuous with each other through the corpus uteri, and were partially separated by an

imperfect septum, which projected from the inferior wall. Owing to the great distension of the left cornu, this septum was pushed to the right, so that the os uteri opened directly into only the gravid horn. The chorion extended from the end of the gravid to that of the non-gravid cornu. As it passed through the corpus uteri it was somewhat constricted by the projecting septum. In the whole length of the non-gravid horn, and at the free end of the gravid horn, the chorion was raised into strong longitudinal folds, which corresponded in reverse order with a similar series of folds of the uterine mucosa radiating from the orifices of the Fallopian tube. At the os uteri the mucosa was raised into strong folds, which radiated into the gravid chorion for a considerable distance, and in some parts of their extent projected as much as 3 inches from the general plane of the mucosa, though at the os they had not more than one half that projection. The chorion in apposition with this part of the mucosa was also folded. In the gravid horn opposite the foetus, where the expansion both of chorion and uterus was the greatest, the folds were not present. Except in a few localities, to be immediately specified, the whole of the extensive surface of the chorion was so covered with vascular villi that, to the naked eye at least, no non-villous intervals could be recognised. The chorion was adherent to the uterine mucosa, so that gentle traction was needed to draw them asunder; and, as the one was peeled off the other, the villi of the chorion were seen to be drawn out of multitudes of crypts opening on the free surface of the mucosa.

The chorion, which lay opposite the os uteri and the immediately. surrounding mucous membrane, was for the most part not villous, but presented a smooth, feebly vascular appearance, which contrasted strongly with the adjacent villous chorion. This smooth spot was irregular in form, measured 6 inches by 4 inches, and from it narrow bands of smooth chorion radiated outwards for from 2 to 3 inches between the villous covered folds of the chorion. It was similar to, but much larger, than the corresponding spot in Orca and the Mare. Small isolated patches of villi were scattered irregularly over the surface of this smooth spot. The inner surface of the chorion at the bare patch was lined by the amnion and not by the allantois. Three inches from this large spot a bare patch, 1 inch by inch, was completely surrounded by villous chorion.

VOL.IX.

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