D I D E L 
the remaining part naked ; forefeet fiirnifhed with five 
toes; hind feet with four and a thumb, with a daw; 
length from the nofe to the tail fifteen inches ; the tail 
about nine. Native alfo of New Holland. 
19. Didelphis volans, the flying opoirum : a beautiful 
fpecies, clothed with fur of the moft exquifite texture ; 
difcovered in New South Wales. Its length, from the 
tip of the nofe to the root of the tail, is twenty inches; 
the tail itfelf is twenty-two inches, at the bafe quite 
light, increafing gradually to black at the end ; the ears 
are large and erect; the coat or fur is of a rich texture ; 
appearing, on the upper parts of the body, at firft fight, 
of a glofl'y black, but on a nicer infpeCtion it is found to 
be mixed with grey; the under parts are white, and on 
each hip is a tan-coloured fpot about the fize of a (hil¬ 
ling ; at this part the fur is thinneft, but at the root of 
the tail it is fo rich and clofe that the hide cannot be felt 
through it. The fur is alfo continued to the claws. On 
each fide of the body is a broad flap or membrane, as in 
the flying fquirrels, which is united to both the fore and 
the hind legs. The jaws are furnifhed with teeth, placed 
as in fome others of this genus: in the upper jaw for¬ 
wards are four fmall cutting teeth, then two canine teeth, 
and backwards five grinders ; the under jaw has two long 
large cutting teeth, five grinders, with no intermediate 
canine teeth, the fpace being quite vacant. The fore 
legs have five toes on each foot, with a claw on each ; 
t;he hinder ones four toes, with claws, (the three on .the 
outfide without any reparation,) and a thumb without a 
claw, enabling the animal to ufe the foot as a hand, as 
nioft of the opoflum tribe are obferved to do. 
20. Didelphis fciurea, the fquirrel opoflum ; with a 
lateral flying membrane; body grey above, fnowy be¬ 
neath ; tail prehenfile, very hairy, black towards the tip. 
Found alfo in New Holland; torpid by day, aCtive by 
night. Size of a fquirrel; eyes black, full; ears round, 
thin; membrane edged with blackifh ; pouch, or falfe 
belly, large ; thumb of the hind feet rounded, unarmed ; 
a black ftripe down the head and back ; two interior toes 
of the hind feet joined. 
2r . Didelphis macroura, the long-tailed opoirum. This 
has alfo a lateral flying membrane; body dark-grey 
above, whitilh beneath ; tail long, flender, black. Na¬ 
tive of New Holland; lefs than the laft, but refembles 
it in manners and appearance. 
22. Didelphis pygmaea, the pygmy opoflum : furniihed 
likewife with a lateral flying membrane; tail flat, pin¬ 
nate, linear. This alfo is one of the newly difcovered 
fpecies belonging to New Holland, and is about the fize 
of a moufe; body brown above, whitilh beneath; 
y/hilkers long ; tongue large, long, flattened ; pouch or 
falfe belly femilunar at the opening. 
In the opoflum tribe, the mode of geflation and nou- 
rifhment of the foetus, has long been a fubjeCt of curious 
inveftigation tp the naturalift; though the economy of 
nature in this very Angular inftance, is far from having- 
been fatisfaftorily explained. It is certain, that during 
the ftate of pregnancy, the mother ejects the foetus from 
the womb, and, by fome fecret aCtion of the parts, con¬ 
veys it into the pouch or falfe belly, wherein the teats 
are fituated. The young at this time are fmall, blind, 
and naked, apd apparently inanimate ; fo that it is necef- 
fary they fhould continue in this outward receptacle 
which nature feems to have provided for them, until 
they attain maturer ftiape, flrcngth, fight, and hair, and 
are prepared to undergo what to them may be called a 
fecond birth. After this, and during their nonage, they 
run into this ppnclj, as into ap afylum, in time of danger, 
and the parent carries them about with her. During the 
time of this fecond geflation, the female (hews an excef. 
five attachment to her young, and will fuffer any torture 
rather than permit the place pf their retreat to be laid 
open ; for fhe has the faculty of dilating or clofing it at 
ple^furejby the influence of fome very powerful mufcles. 
p H r s. s oY 
Everard Home, efquire, in a Paper read before the 
royal fociety of London, in March 1795, and publiflied 
in their Tranfa&ions of that year, has unqueftionably af¬ 
forded the beft information hitherto given on this inte- 
refting fubjeCt. In quadrupeds in general, he obferves, 
the ovum containing the embryo, as foon as it arrives in 
the uterus, becomes attached to the internal furface, and 
the foetus owes its increafe and fupport to a connection 
with that vifcus, by means of the placenta and navel 
firing. In the bird, the fnake, the lizard, the tortoife, 
and in fifh, the nidus of the embryo, even before its im¬ 
pregnation, is detached from the mother, and the foetus 
receives its future fupport from the animal fubftance in 
which it is enveloped. But the fcetus of the opoflum 
tribe will be found neither to derive its fupport from a 
connection with the uterus in which it is depofited, like 
other quadrupeds, nor to refemble, in the mode of its 
nourifhment, the young that is hatched from an egg, but 
to have a mode of fupport peculiar to itfelf. The Vir¬ 
ginian opoflum was the only one of this tribe that was 
known in Europe before the late difcoveries in the South 
Seas ; and as it had not been found to breed either in 
France or England, the only accounts of its mode of ge¬ 
neration were thofe received from America, which were 
vague, and could not be depended on. Thefe accounts, 
however, led anatomifts, who had opportunities of dif- 
fecting the female organs, to endeavour by that method 
to arrive at faCts ; but the parts were found to be fo com¬ 
plex, and in fo many refpeCts different from thofe of 
other quadrupeds, that nothing fatisfaCtory could be 
made out, while deprived of an opportunity of feeing 
them in an impregnated ftate. The difeovery of the kan- 
guroo, in our fettlement of New South Wales, opened 
a profpeCt of afeertaining more fatisfactorily the genera¬ 
tion of thefe animals ; and from the time that colony was 
eftablifhed, it became an inquiry to which feveral phyfi- 
ologifts direfted their attention. The late Mr. Hunter 
had for many years kept American opoffums, with the 
foie view of inveftigafing this fubjeCt; but was never 
able to induce them to breed, though every means in his 
power were employed for that purpofe. 
In the fumnrer of 1794, Mr. Home received from Mr. 
Lang and major Nepean, who had appointments at Port 
Jackfon, feveral preparations of the uterus in different 
ftates, and the young kanguroo at a very early period af¬ 
ter leaving the uterus. Thefe certainly appear to eluci¬ 
date feveral parts of the curious mode of generation of 
this animal, and to contain very material anatomical faCts 
to direCI future inquiries. Thefe faCts are, that the kan¬ 
guroo breeds at all feafons; that the female has never 
been known to have more than a (ingle young one at a 
time, and is feldom found without one. That the young 
remains in the falfe belly, or goes into it occafionally, 
and fucks the mother a long time after it appears capable 
of procuring its own food ; and yet if the mother is clofely 
purfued, in attending to heir own fafety,' (lie forces the 
young out of the falfe belly, provided it has arrived at 
a fufficient age to be covered with hair. There are two 
male and feveral female kanguroos at the royal menagerie 
at Richmond, and fome of the females have bred iincc 
they came there. Mr. Home vifited them at different 
times, and found that none of them have had a young 
one oftener than once in twelve months; and the young 
appears to be nine months old befora it entirely leaves 
off fucking the mother. One of the females bred at 
Richmond had a young one in the falfe belly when only 
about a year and half did. The young, after it is ex¬ 
cluded from the falfe belly, and another is depofited in 
if, continues to put in its head and fuck for a month or 
two longer. 
The female kanguroo has only two mammae, but each 
of them has two nipples ; they are not placed upon the 
abdominal mufcles as in mod other quadrupeds, but are 
fituated between two moveable bones connected with the 
cs pubis, peculiar to this tribe of animals ; and they are 
fupported 
