of ova, of which a recent instance had occurred in the ovarium, fig. 549.

The remnant of the Wolffian body, noticeable in most lower Mammals in the form of a

549

group of parallel wavy tubules extending from the Ovary between the layers of the broad ligament, is constantly present in the human subject, and is termed 'parovarium,' fig. 550, a, b, c, d, the terminal cæcum becoming enlarged, as at f, to form the so-called 'hydatid' of the broad ligament: contiguous cæca, b, have a tendency to become dilated: those at the opposite end become atrophied, d, as does likewise the duct e, the terminal portion of which, known as Gärtner's canal' in lower Mammals, can seldom be recognised in the human

550

female.

Ovarium and parovarium, Luman; nat size. CCXLVI".

The pavilion or abdominal aperture of the oviduct (Fallopian tube,' Anthr., fig. 548, d) is richly provided with a fringe of irregularly crenate folds radiating from the beginning of the canal: the duct dilates beyond this orifice, and then gradually contracts to almost capillary minuteness: the surface of the lining membrane of the tube is augmented by the folds continued from the fimbria, and chiefly longitudinal in direction; these subside about an inch from the uterus, where the oviduct again begins slightly to dilate: where it enters the uterus the longitudinal impressions terminate abruptly: the epithelium of the lining

membrane is ciliate. Such is the structure of the human oviduct, as shown in the preparation, No. 2823, A, xx. vol. iv. p. 189; but there are varieties, as in fig. 550. A remnant of the primordial oviduct, or duct of Müller,' is constant, in the form of the pedunculate hydatid, fig. 550, i,

The human uterus, of the shape and dimensions shown in the sections, figs. 551 and 552, is more compact, more muscular, than in Quadrumana, has a broader and more convex fundus, a more marked constriction between the incubating and transmitting parts, and these are more distinct in their respective structures. The former, fig. 551, uc, which is analogous to and homologous with

the cornua uteri' of brutes, is termed, in Anthropotomy, the 'body' the part, ib. c c, which answers to the corpus uteri' in brutes, fig. 546, b, c, d, is termed cervix uteri.' The relations above enunciated receive an interesting confirmation in the occasional anomaly of the human uterine structure shown in fig. 541.

The enlargement for the lodgment of the foetus and its appendages is limited to the incubatory part, the inner surface of which in the unimpregnated womb is smooth, and by contact closes the cavity, as at i, fig. 552. The cervix, i, p, has its inner surface increased by numerous plicate folds and furrows; in many instances diverging from an anterior and posterior medial longitudinal

ridge; and here a slender fusiform cavity, occupied by secretion, is maintained.

What is called the lining membrane' of the uterus is a layer of substance, fig. 570, including formified corpuscles or nuclei,' fusiform fibres, and amorphous matter traversed by the irregular tortuous canals, called utricular glands or follicles,' and by capillary blood vessels, which form an angular network, fig. 553, on the surface, the utriculi' opening in the centre of

the meshes. This substance is readily shed as 'decidua,' and renewed. At the 'cervix' a true

553

lining membrane' becomes differentiated, composed of basilemma, fibrous and vascular tissues, follicles, and papillæ, the free surface showing a precipitate of tessellated epithelium. The os uteri' is a transversely elliptic convex protuberance, upon which the womb communicates with the vagina by a transverse fissure. It is directed obliquely backward, and when divided, as in fig. 552, presents an 'anterior lip,' a, and a 'posterior lip,' p. The posterior commencement of the vaginal canal, f, overarching the os uteri,' is called 'fornix.' The peritoneum is continued over this part as far as the line or reflection upon the rectum, r. Anteriorly, the peritoneum is reflected from the uterus at the beginning of the cervix, which, from b to b, is connected to the urinary bladder by areolar tissue. The round ligament of the uterus consists of fasciculi of unstriped fibres, continued from those of the angles of the fundus uteri,' fig. 548, g, inclosed by peritoneum, and continued to the internal inguinal ring: here it expands, and separates into an inner fasciculus lost in the tendons of the internal oblique and transversalis, a middle one in the upper column of the external abdominal ring, and an external one to the inferior column. It is a rudimental homotype of the cremaster of the male in its primitive inverted state. Anthropotomy extends the term ligament' to the different sheets or folds of peritoneum continued or reflected from the uterus. One of these incloses the ligament of the ovary continued upward into the remnant of that of the primordial kidney. The vagina is a subdepressed cylindrical canal, commencing as in fig. 552, and continued to near the vulval outlet, where it is bounded anteriorly by the prominence of the vestibule on which the urethra opens, fig. 554, u, and posteriorly by the usually crescentic fold, which more or less constricts the distal orifice of

the vagina, ib. va. The inner surface of the vagina presents numerous close-set, transverse, often verrucose, rugæ, sometimes diverging from opposite longitudinal tracks, as columnæ rugarum,' on the fore and back parts of the walls: toward the vulval end of the canal the ruga become broken up into shorter prominences, or leaflets.' This part of the vagina is surrounded by a 'constrictor' muscle, fig. 554, b, between which and the inner

554

membrane, ib. va, there
is, on each side, a gland,
g, which sends its secre-
tion by the duct, d, into
the urogenital passage,
between the hymen and
nymphæ: it is called the
' vulvo-vaginal' gland,
and answers to Cow-
per's' in the male. The
urogenital passage rare-
ly exceeds an inch in
length: it includes the
prominence or
or vesti-
bule,' ib. v, upon which
the urethra opens; the
clitoris, c, with its pre-
putium, pc; and the
pair of highly vascular
folds, n,' continued from
the clitoris downward to
the lower boundary of
the passage. The vulva

is chiefly composed by the labia,' ib. 7 (the right one has been removed in the figure), which are lateral folds of tegumentary and dartoid' tissue, including fibrous and adipose substance. The outer part is hairy skin, the inner layer is smooth, vascular, pinkish in colour, and furnished with many muciparous and sebaceous follicles. Above their upper commissure is an eminence of fibrous and adipose tissue, covered by integument which, at the age of puberty, becomes clothed with hair. The labia are homotypes of the scrotum: the clitoris is a miniature representation of the penis, and has its crura,'' body,'' glans,'' suspensory ligament,' erectores muscles,' and closely conformable vascular structures, with the addition of large contiguous venous plexuses. Its nerves are equal in size to those of the penis.

6

1 These, called 'nymphæ,' are of unusual length in some low varieties (Hottentot, Boschismen) of the human species.

CHAPTER XXXVIII.

GENERATIVE PRODUCTS AND DEVELOPMENT OF MAMMALIA.

As the leading forms of the Mammalian spermatozoa have been already given, and as their development does not differ in any essential degree from the process described in Vol. I. pp. 589-592, I proceed to notice the correlative act which is truly characteristic of the present class.

395. Ovulation in Mammalia.-The ovum in Mammals, characterised by its extreme minuteness, was recognised soon after the microscope came into use. De Graaf (1672) discovered it in the oviduct of the Rabbit. Haller,2 unsuccessful in this quest, lent his authority to discredit the statements of the Dutch anatomist; but Cruikshank3 (1797) confirmed and established their accuracy. Nevertheless, up to 1824, the Mammalian ovum was known only as it appeared in the oviduct.

Prevost and Dumas, indeed, twice detected a less pellucid spherical corpuscle, a millimeter in diameter, in the ovarian or Graafian follicle, and deemed it very probable that thence was derived the oviducal ovule. Von Baer (1827) raised the probability to scientific certainty by a series of observations of the ovarian ovum, made in the Bitch, Cow, Sow, Ewe, Rabbit, and also in the Human female. He deemed, however, this ovarian ovule to answer, not to the entire ovum of lower Vertebrates, but to the germinal vesicle' of such; the fluid of the Graafian vesicle he homologised with the yolk,' and its lining membrane with the membrana vitelli,' so that the Graafian vesicle' was still to Von Baer, as to Prevost and Dumas, the ovum of the ovary.'s Soon followed, however, an almost simultaneous series

6

2 CCLVII".

3 CCLVIII".

CCLIX".

1 CCLVI". Vesicula ergo Graafiana cum ad ovarium generatimque ad corpus maternum respiciamus, ovum sane est mammalium. Sed evolutionem quod attinet, vehementer discrepat a reliquorum ovo animalium, quorum ovi nucleus integer ex ovario devehitur, fetui nascituro non sedem tantum præbiturus sed in ipsum potius fetum transformandus. In mammalibus vero vesicula innata vitellum magis excultum continet et ratione ad fetum geniturum habita verum sese probat ovum. Ovo fetale dici possit in ovo materno. Mammalia ergo habent ovum in ovo aut, si hac dicendi formula uti licet, ovum in secunda potentia.-P. 32. Quapropter in vesicula Graafiana describenda