6^5 
of twins. Dr. Hunter, who had frequent opportunities of 
.examining the ovaria with care in feveral cafes of twins, 
’.always found two corpora lutea. In fome of thefe cafes 
there were two diftintt corpora lutea in one ovarium ; in 
.others, there was a diftimft corpus luteum in each ovari¬ 
um. In a variety of different cafes, it has been found that 
the fex of the foetus has no relation to the corpus luteum 
being' in the right or left ovarium. 
Thofe who fay that the uterus grows thicker in the fame 
proportion that its bulk is increafed, have probably been 
deceived by examining the uterus of a woman who died 
fome hours or days after delivery. In that contracted date 
the uterus is often found even two inches thick ; but in 
all thofe Dr. Hunter examined, in the natural diftended 
.date, though there w as fome difference, the thicknefs of 
the uterus was but a little more confiderable than before 
impregnation. When not injeCted, its more common thick- 
nels is from one,to two thirds of an inch ; w hen its veffcls, 
and particularly its veins, are pretty well filled with wax, 
its thicknefs is thereby confiderably increafed, more efpc- 
cially where the placenta is fixed, on account of the num¬ 
ber and fize of the vefiels at that part. For this reafon 
only, perhaps, the uterus is thickeft at that part, and for 
this reafon too it is commonly thicker towards the fundus 
titan the cervix. In refpeCl of thicknefs, a good deal of 
variety has been obferved, and fuch inequalities in the 
.fame uterus, that, even where the placenta did not adhere, 
the uterus has been almofi twice as thick at one part as at 
another. We have always obferved in opening the ute¬ 
rus, that its thicknefs is more confiderable than one could 
have imagined it to be by feeling it externally, where there 
is a fluctuation of the water. Its fubftance is fo loft, that 
the fluctuation then felt is like that of water in a thin 
bladder. 
To fhew the elevated pofition of the womb in advanced 
pregnancy, and its fituation with refpeCt to the ligaments, 
tubes, inteffines, and whole mafs of the abdominal vifcera, 
Pr. Hunter has furnifhed an elegant Difi'eCtion of the 
Parts, which we have given in Plate III. of the Gravid 
Uterus, and of which the following is an explanation. 
AA, The thighs cut through. B, The back bone cut 
through above the diaphragm. C, Part of the eighth rib. 
DD, The integuments and nuifcles at the back-part of the 
chefi. E, The inferior flap of the abdominal mufcles, &c. 
F, Part of the mons veneris, turned afide with the abdo¬ 
minal mufcles. G, Tlie refpeCHve part of the left fide. 
II, The margin of the chefi covered by the peritoneum 
and mufcles, which are turned over it. I, The enfiforin 
cartilage. KK, The lower ribs and other containing 
parts, cut down longitudinally. L, The poflerior and 
lower part of the right cavity of the chefi. M, The trunk 
of the defeending aorta. N, The oefophagus. O, The 
upper convex fur face of the diaphragm. P, That part of 
the centrum tendinofum of the diaphragm which is in the 
right lidc. Q^The trunk of the lower cava tied, clofe to 
the upper furface of the diaphragm. RR S The cut edge 
of the pleura. SS, The cut edge of the peritoneum. T, 
The iniide of the tranverfus mulcle covered with the pe¬ 
ritoneum. U, The great or right lobe of the liver. V, 
The fmal! lobe of the liver. W, The falciform ligament, 
or remains of the umbilical vein, cut oft’ as it enters the 
fifilire of the liver. X, The colon palling up from the 
caecum to the liver. YY, The coion with its appendicu- 
lie adipofc running towards the left fide. ZZ, The be¬ 
ginning or root of the omentum. aaaa t The fmail intef- 
t ines brought to view by cutting off the omentum a little 
below the edge of the liver. 6 , The womb; upon its fur- 
face we can trace, though obfeurely, its veins, c, The 
round ligament running clown to its pufiage into the groin. 
d, The Fallopian tube running backwards on the iniide of 
the os ilium, c, The fimbriated end of the tube, lying be¬ 
hind the fide of the womb, f. The prominent corner of 
the womb, where the buttocks or loins of the child were 
difiinftly felt before the part was opened. 
[Gravid Uterus. 
Of the VESSELS of the GRAVID UTERUS. 
There is no circumftance in which the gravid uterus 
differs more from the unimpregnated ftate, than in the lize 
and termination of its vefiels. The arteries, both fiper- 
matic and hypogaffric, are very much enlarged. The iiy- 
pogaffric is commonly confiderably larger than the fper¬ 
matic, and we very often find them of unequal iizes in the 
different fides. They form a large trunk of communica¬ 
tion all along the fide of the uterus; and from this the 
branches are fent acrofs the body of the uterus, both be¬ 
fore and behind. The cervix uteri has branches only from 
the hypogaffrics, and the fundus only from the fpermatics; 
or, in other words, the hypogaffric artery gives a number 
of branches to the cervix, befides fending up the great 
anaftomofing branch, pnd the fpermatic artery luppiies the 
tube and fundus uteri before it gives down the anaftomo- 
fing branch on the lateral parts of the uterus. All through 
the fubftance of the uterus there are infinite numbers of 
anaftomefing arteries, large and fmail, fo that the whole 
arterial fyffem makes a general net-work, and the arteries 
are convoluted, or ferpentine, in their courfe. Hardly any 
of the larger arteries are feen for any length of way upon 
the outfide of the uterus. As they branch from the fides* 
where they firft: approach tire uterus,- they difappear by 
plunging deeper and deeper into its fubftance. 
The veins of the uterus would appear to be ftill more 
enlarged in proportion than the arteries. The fpermatic 
and hypogaftric veins in general follow the courfe of the 
arteries, and like them, anaftomofe on the fide of the ute¬ 
rus. From thence they ramify through tire fubftance of 
the uterus, running deeper and deeper as they go oil, and 
without following precifely the courfe of the arterial 
branches. They form a plexus of the largeft and mod 
frequent communications which we know of among the 
velfels of the human body. And this they have in com¬ 
mon with the arteries that their larger branches go to, or 
rather come from, that part of the uterus to which the 
placenta adheres; fo that when the venous fyftem of the 
uterus is well injected, it is evident that that part is the 
chief fource of the returning blood. Here too, both the 
large and fmail veins are continued from the placenta to 
the uterus, and are always necedarily broken upon the re¬ 
paration of thefe two parts. The veins are without valves, 
and are therefore eafily injected. In injecting them, we 
oblerve that at firft they become turgid, and projeft on the 
outer furface of the uterus; but in proportion as we throw 
a greater quantity of wax into thefe vefiels, they grow 
more flat and obfeure ; becaule the uterus itfelf becomes 
more filled and tenfe, which has the efteft of compreillng 
the veins that run in its fubftance. 
Mr. Cruikfhank is the firft, in this fchool of anatomy, 
who obferved the lymphatics in the gravid uterus ; healfo 
injected them with mercury, and traced them with great 
fuccefs in feveral fubjects. They are more numerous, and 
many of them larger, than could have been imagined ; from 
which it is manifeft, that a copious abforption is carried 
or. in the uterus towards the mother. The lymphatics 
pervade its fubftance univerfally; its peritonaea} coat ap¬ 
pears, like that of a calf’s fpleen, to be interwoven with 
a crowded plexus of thefe vefiels ; and where they get to 
the fides of the uterus, when filled with mercury, fome of 
them are even larger than a goofe-quill. Some are re¬ 
markably varicofe, or enlarged at particular places. They 
pafs from the fides of the uterus, many with the fpermatic 
velfels, but the greater number and the larger with the 
hypogaffrics. Of thefe laft, fome pafs into the glands on 
the fide of the vagina; others meet with no glands till they 
have reached the fide of the pelvis, where they run into 
the glands of the iliac plexus, or fiioot backwards into the 
glands of the facral plexus ; from both of which they pafs 
in’o the lumbar plexus, where they are loll among the 
aofprbents of the lower extremities, and the external parts 
of generation, 
3 Befides 
ANATOMY, 
