^{page 71 note *} Ueber den Embryo der Affen und einiger anderen Säugethiere, in Abhandl. der Akad. der Wissensch. zu Berlin, 1828.

^{page 71 note †} Erläuterungs Tafeln zur Vergleich. Anatomie Heft III. Plate IX. Leipzig, 1831.

^{page 71 note ‡} Ueber Entwicklungs-Gescbichte der Thiere, p. 263. 1837.

^{page 72 note *} Annales des Sciences Naturelles, p. 98, vol. i. 1844.

^{page 72 note †} Vol. ix. p. 563. Paris, 1870.

^{page 72 note ‡} Philosophical Transactions, 1857, p. 352.

^{page 72 note §} Sect Vol. iii. p. 731.

^{page 72 note ║} Medical Times and Gazette, May 30, 1863, p. 555, and Elements of Comparative Anatomy, p. 111, 1864.

^{page 72 note ¶} London, 1869, p. 104.

^{page 73 note *} Trans. Zoological Soc. vol. v. p. 303. 1863.

^{page 73 note †} Handbuch der Zoologie. Band I. 65. Leipzig, 1868.

^{page 73 note ‡} Natürliche Schöpfung's Geschichte. Berlin, 1868.

^{page 73 note §} I wish to take this opportunity of thanking Dr Ridpath not only for the above specimen, but for a number of other valuable zoological objects from Central America which he has from time to time presented to the Anatomical Museum of the University.

^{page 73 note ≑} Monats. Berichte Berlin Akad. 1858, p. 128, and 1864, p. 679 ; and Natural History Review, vol. v. p. 299. 1865.

^{page 75 note *} To prevent any misunderstanding, I may state that in this and in my previous memoirs on the placenta, I use the term chorion, in the ordinary descriptive sense, to express the outer envelope of the fœtus, without committing myself to any theory of the mode of production of this membrane.

^{page 77 note *} I adopt here the descriptive terms introduced by Professor Rolleston.

^{page 81 note *} Lehrbuch der physiologischen Chemie. Leipzig, 1868, p. 195.

^{page 81 note †} Quart. Journal of Microscopic Science, vii. p. 127.

^{page 75 note †} Journal of Anatomy and Physiology, ii. p. 1.

^{page 85 note *} See Eschricht's Essay, “ Ueber die Richtung der Haare,” in Müller's Archiv., 1837, p. 42.

^{page 85 note †} Müler's Archiv., 1841, p. 370.

^{page 85 note ‡} Ueber die Entwicklung und den Bau der Haut und der Haare bei Bradypus, in Abhand. der Naturforsch. Gesellschaft zu Halle. Bd. ix., 1864.

^{page 86 note *} Through, the kindness of my friend, Dr John Young, Professor of Natural History in the University of Glasgow, I was enabled, in the month of July, to examine a foœtus of Bradypus tridactylus in the Hunterian Museum in that University, though not one of Dr William Hunter's specimens. The fœtus was 9½ inches long from nose to tip of tail. It was covered with hair, and possessed a complete epitrichium similar to the larger of the two specimens figured by Welcker in his Memoir. The placenta, though greatly shrivelled and hardened by the prolonged action of spirit, was seen to be composed of a number of discoid lobes.

^{page 87 note *} Abhand. der Akad. der wissensch. zu Berlin, 1828, pp. 40, 41.

^{page 88 note *} November, 1873.—This section has been re-written and added to since the paper was read.

^{page 88 note †} Anatomy of Vertebrates, iii., p. 731. 1868.

^{page 89 note *} P. 104. London, 1869.

^{page 89 note †} Analecten für Vergleich. Anatomie. Zweite Sammlung, p. 54. Bonn, 1839.

^{page 89 note ‡} Leçons sur la Physiologie, ix. part 2, p. 563, note. Paris, 1870.

^{page 89 note §} Annales des Sciences Naturelles, xv. 1872.

^{page 90 note *} P. 112. London, 1864.

^{page 91 note *} As described and figured in my memoirs in the Transactions of this Society, vol. xxvi. pp. 207 and 467, 1871.

^{page 91 note †} The presence of these uterine pouches in Manis is not without interest to the human anatomist, and may serve to throw some light upon the mode of production of some cases of so-called extra-uterine gestation, described by obstetrical writers, in the human female. It is not, I think, improbable that in some of the cases figured and described by Breschet (Répertoire Général, 1826), the ovum may have been lodged in a pre-existing uterine pouch, and not, as he supposed, in the thickness of the walls of the uterus, and the same explanation may perhaps be given to Dr Braxton Hick's case in Trans. Obstetrical Soc. of London, vol. ix. p. 57. Cases which have been described as tubo-uterine pregnancies may also have had a similar mode of origin.

^{page 94 note *} I am aware that Eschricht, in his important memoir (De Organis, &c, p. 24),speaks of the vessels in the feline placenta as exhibiting dilatations, and that Kölliker (“ Entwicklungs Geschichte,” p. 163), states that in the bitch the maternal blood-vessels are very strongly developed, and appear as very thin-walled capillaries ⅙′′′ in breadth, but I have not seen in the placenta of this animal vessels at all comparable with the sinuses in the sloth.

^{page 94 note †} Beiträge zur Entwicklungs Geschichte des Meerschweinchens in Abhand. der König. Akad. der Wissensch. zu Berlin, 1861.

^{page 94 note ‡} Lehrbuch der Histologie, p. 517. 1867.

^{page 94 note §} Sur les Glandes Utriculaires de l'Uterus, p. 10. French translation. Algiers, 1869.

^{page 94 note ║} Op. cit. plates i. ii. p. 117, and MÜller's Archiv. p. 80. 1848.

^{page 94 note ¶} Sulla le Glandole Otricolari dell'Utero. Mem. dell'Acad. delle Sc. di Bologna, p. 26. 1873.

^{page 94 note **} The naked-eye appearance of the folds of the mucous membrane of the rabbit's uterus has been carefully described and figured by M. H. Hollard, in Annales des Sciences Naturelles, p. 223. 1863.

^{page 95 note *} Annales des Sciences Naturelles, xv., 1871.

^{page 95 note †} Since this Memoir has been put in type my attention has been directed by Prof. R. O. Cunningham to a paper “ On the Lemurs,” by Mr St George Mivart, in Proc. Zool. Soc. London, May 20th, 1873. Mr Mivart states that from a private communication made to him by M. Alphonse Milne-Edwards, that naturalist is now of opinion that the Lemuroids have no decidua, and that the placenta is diffuse. It does not appear from Mr Mivart's paper whether M. Milneedwards had received additional specimens since the publication of his Memoir quoted in the text, in which, when describing the uterine mucosa of Propithecus, lie says, “ Et la surface en est hypertrophiée de façon à former une couche caduque, trés-analogue à celle qui, dans une trés-faible étendue, adhère au placenta discoïde des Singes, des Insectivores et des Rongeurs.” From which extract it is clear that when his Memoir was written, M. Milne-Edwards had no doubt of the presence of a decidua.

^{page 96 note *} Figures of the placenta in the Quadrumana, or descriptions of its naked-eye characters, will be found in John Hunter's Collected Works, iv. 71 ; Plates xxxv., xxxvi., and fig. 2, xxxiv. ; in Rudolphi's Memoir, “ Ueber den Embryo der Affen,” already quoted ; in Breschet's important Essay in Memoires de l'lnstitut, 1845, xix. ; and in Owen's Comparative Anatomy of Vertebrates, iii. 747, in which volume it is mentioned that the pregnant monkey, dissected by Hunter, the name of which that anatomist had omitted to give, was a specimen of Macacus rhesus.

^{page 96 note †} Compare Bkeschet's description of Simia Sabaea with that of Simia nasua, pp. 444, 470.

^{page 96 note ‡} Mem. Dell' Acad. di Bologna, 1870, p. 53.

^{page 97 note *} Répertoire Général, p. 3, Paris, 1826.

^{page 98 note *} See Hecker, as quoted by Dr J. Matthews Duncan in “Edinburgh Medical Journal,“ Nov. 1873.

^{page 98 note †} Reichert und du Bois Reymond's Archiv. p. 127. 1873.

^{page 98 note ‡} The arrangement in the sloth is, indeed, not unlike what E. H. Weber conceived to he the arrangement in the human placenta.

^{page 98 note §} Lectures on the Development of the Gravid Uterus, p. 62, figs. 19, 20. London, 1860.

^{page 99 note *} Abstract in Proceedings of that date, and more fully in Journal of Anatomy and Physiology, November 1872.

^{page 100 note *} Dr Priestley states (p. 27) that he could see them distinctly in the parietal decidua near the seat of the placenta in the 3d month, but they were undergoing granular degeneration, and, instead of being lined with epithelium, were filled with granules and molecules.

^{page 100 note †} Trans. Roy. Soc. Edinburgh, vol. xxvi. p. 467.

^{page 101 note *} Reade Lecture “On the Classification of the Mammalia,” p. 31, 1869.

^{page 101 note †} Considérations sur les affinités naturelles et la classification methodique des Mammifères, being the first chapter in the Rechérches pour servir a l'histoire naturelle des Mammifères, now in course of publication by himself and his son M. Alphonse. Preface, dated 27th April, 1868. Paris.

^{page 101 note ‡} Natrliche Schöpfungs-Geschichte. Berlin, 1868, p. 480.

^{page 102 note *} Ostéographie des Mammifères. Paresseux, p. 1.