318 
formation, and at the same time to have been 
coincident with a completely divided uterus.* 
It is not unusual to find the vagine of the 
Kangaroo distended with a gelatino-mucous 
adhesive secretion containing hard irregularly 
shaped fibrous masses. One of these bodies, 
which was found in the mesial cul-de-sac of 
a Kangaroo, was described and figured by 
Sir Everard Homet as the vertebral column 
and occipital bone of a fetus; and peal a 
theory of marsupial generation appears to have 
Seaiendh Scene by this belief Professor 
Leuckart,} who found similar bodies in the 
vaginal tubes of a Kangaroo, compares them to 
a mola, or false conception, but observes that 
there was nothing in their structure that would 
permit him to form a conclusion that they were 
parts of a foetus. 
In the Wombat the lining membrane of 
the vaginal culs-de-sac is greatly increased by 
innumerable irregular ruge and papillae, the 
urethro-sexual canal is lined by a thick epi- 
thelium, and its surface is broken into count- 
less oblique ruge and coarse ay eg the 
surface immediately surrounding the urethral 
orifice, which in this as in other Marsupials 
is close to the vaginal orifices, is comparatively 
smooth. 
The clitoris is situated in a preputial recess 
near the outlet of the uro-genital passage : it is 
simple in those marsupials that have a simple 
glans penis, but is bifid in those which have 
the glans divided : and in the Opossum each 
division of the glans clitoridis is grooved. 
Development of the Marsupialia.—Before 
proceeding to detail the present received doc- 
trine of the generation and development of the 
Marsupialia, it may not be unprofitable to take 
a rapid glance at the different opinions that 
have prevailed at different periods respecting this 
interesting and difficult part of their economy. 
The minute size of the young of the Ameri- 
can Opossum when first received in the mar- 
supium, their pendulous attachment to the 
nipples, and perhaps the mode in which the 
nipples themselves are developed, gave rise, 
among the earlier observers, to a notion that 
the young were originally formed by and from 
those parts. 
‘And t this belief was not only current then, as 
now, among the unscientific settlers in the colo- 
nies where the marsupial animals are common, 
but was entertained likewise by the best in- 
formed Naturalists of those times. Thus the 
learned Marcgrave, in his account of the Opos- 
sum, says, when speaking of the marsupial 
pouch, “ Hac bursa ipse uterus est Animalis, 
nam alium non habet, uti ex sectione illius com- 
peri; in hac semen concipitur et catuli forman- 
tur.” § And Piso repeats the assertion more 
strongly. “ Ex reiteratis horum animalium 
sectionibus alium non invenimus uterum preter 
* Dr. Parcell, Philosophical Transactions, vol. 
lxiv. p. 478. 
t Philos. Trans. vol. Ixxxv. p. 228. 
Pi ngiag Archiv fur Physiologie, tom, viii. 
p- 442. 
§ Hist, Rerum Naturalium, Brasil. 1648, 
MARSUPIALIA. 
hanc bursam, in qua semen concipitur et catuli 
Jormantur. Quos deinde quinos vel senos simul — 
circumfert, mobiles, perfectos, sed depiles, adeo=— 
que pertinaciter uberibus affivos, ut a perpetua— 
suctu vix avellantur, antequam permittente — 
matre ad pastum ipsi egrediantur.” * ) 
The assertion that the young grow from the 
pipple was again repeated in to the 
Philander Opossum ( Didelphys Philander) by 
Valentin in his History of Amboyna, and has 
even been revived at a comparatively recent 
period.t Some glimpses of the truth were ob- 
tained, however, before the time of the authors 
who have been a a H 
example, speaks of the generation th 
ri ahhen in the same words in h 
Cuviert sums up the then existing - 
ledge of the subject in the second edition of 
his ‘ Régne Animal.’ “ eT quinosve — 
rit catulos, quos utero conceptos, editosque in 
Mies alvi capacitate quadam, dum adhuc par= 
vuli sunt, claudit ac servat.”§ And Mafieius — 
more particularly describes the attachment of 
the young to thenipple. “ Illud autem mi ; 
in Cerigonibus” (Opossums) “ ex ejus alvo dua 
dependent veluti mantice, in iis catulos cit 
cumfert, et quidem adeo pertinaciter suoquem=_ 
que uberi affixos, ut a perpetuo suctu non 
avellantur, antequam ad pastum ipsi per se 
progredi valeant.” || “ 
Nevertheless, as the uterine gestation is here 
simply alluded to without any detailed obser-_ 
vations in proof of it, the assertion was compara-_ 
tively of little value in a scientific point of vi i ? 
and the gemmiparous theory, sup . 
Macao and Biso, ps bore book a 
valent at the time when Dr. Tyson first turned 
his attention to this subject. 4 
The discovery of the true uterus, recorded 
by that learned and accurate anatomist in the — 
20th volume of the Philosophical Transactions, — 
p- 105, was the first step towards a corre ." 
theory of the generation of the marsupial ani~ 
mals. It necessarily caused him to reject the 
gemmiparous theory, but, as often happens in 
such cases, Tyson was led into the orpene me 
sceptical extreme ; and he was also induced 
doubt the really accurate statements of H 
* De Indie utriusque Re Naturali et Me 
lib. v. c. 24, 1658. * 
t See Geoff. St. Hilaire, in the Journal Ce e~ 
mentaire du Dict. des Sciences Médicales, tom. ii Ay 
p- 193 (1819) : « Si les animaux a bourse nai emt 
aux tétines de leur mére.” 
¢ ‘‘ La premiére de toutes leurs particulari 
est la production prématurée de leurs petits, qi 
naissent dans un état de développement a p pine 
comparable a celui auquel des foetus ordinaires par- 
viennent quelques jours aprés la conception. In- 
capables de mouvement, montrant a peine des — 
germes de membres et d’autres organes extérieures, — 
ces petits s’attachent aux mamelles de leur méreet _ 
y restent fixés jusqu’ace qu’ils se soient dével 
au degré auquels les animaux naissent ordinaire- 
ment. Presque toujours la peau de l’abdomen est 
disposée en forme de poche autour de ces mamelles, 
et ces petits si imparfaits y, sont préservés, comme — 
dans une seconde matrice.” Régne Animal, 1829, 
vol. i. p. 172. 
i Hist. Mexican. lib. ix. p. 330. 
| Joh. Petr, Maffeius, Hist. Indica, 
