PAG 
Great quantities of thefe Oyfters are fent to Lon- 
don, to Holland, V/eftphalia, and the adjacent 
countries.' 
The Oyfter affords a very pleafing entertain- 
ment in microfcopic obfervations. In the clear 
liquor many little round animalcules have been 
found, whole bodies being conjoined, form fphe- 
rical figures, with tails, net changing their place 
otherwife than by finking to the bottom, as being 
heavier than the fluid; thefe have been feen fre- 
quently feparating, and then coming together 
again. In other Oyfters, animalcules of the fame 
kind were found not conjoined, but fv/imming by 
each other ; v/hence they feemed in a more perfccfl 
ftate, and were judged by Lewenhoeck to be ani- 
malcules in the roe or femen of the Oyfter. 
A female Oyfter being opened, incredible mul- 
titudes of fmall embryo Oyfters were feen, co- 
vered with little fliells, perfeftly tranfparcnt, and 
fwimming along (lowly in the liquor j and in ano- 
ther female, the young ones were found of a 
browner colour, and without any appearance of 
life or motion. However, Lewenhoeck's obfer- 
vations, with regard to the fexes of Oyfters, are 
not generally received in this age of more accu- 
rate enquiry : it is now commonly believed that 
they are felf-impregnated, and that the diftinftion 
of fexes is only founded on hypothetical grounds. 
OYSTER-WORM. An appellation given 
by naturalifts to a kind of fmall Worm found in 
Oyfters, which fhines in the dark like the glow- 
worm, but with an univerfal light, and not in part 
only. 
P A C 
M. De Lavoye firft difcovered thefe Oyfter^ 
Worms; who, communicating his obfervations to 
M. Auzout, gave occafion to a very diftinct ac- 
count of them from this laft-mentioned gentle- 
man. The firft- thing that prefents itfelf on the 
opening of the Oyfters which contain thefe 
Worm.s, is only a fort of fliining clammy moif- 
ture, appearing like a ftar of a blueifh colour; 
and which, being drawn out, will extend itfelf to 
near half an inch in length, and ftiine as much for 
tliat whole length as in the contracted ftate: it 
will alfo exhibit it's radiance for fome time after 
it is taken out of the Oyfter. 
On a more minute inveftigation, thefe fhinina" 
fubftances are found to be real living Worms, of 
which there are three diftinft fpecies. One fort 
is whitifli, and has twenty-four or twenty-five 
feet on each fide ; there is a black fpeck on one 
fide of the head ; and the back exaftly refembles 
that of an eel when the ficin is ftripped ofi^. The 
black fpeck in the head is unqucftionably an eye, 
and it is remarkable that the creature has but one. 
The fecond fort of thefe Worms is red : the body 
is compofed of feveral^ rings; the nofe is like that 
of a dog; and, like the former, it has but one eye, 
and a fimilar number of feet. The third fort is 
very different from the other two: it is fpeckled; 
and it's head has a tuft of hair on each fide. 
There are other Worms found in the Oyfter; 
particularly a large greyifh one, v/ith two horns, 
a large head, and feven or eight v/hitifli feet; but 
thefe do not ftiine. This light more frequently 
occurs in large than in fmall Oyfters. 
|AC A ; the Mus Paca of Linnseus. This ani- 
_ mal is of the Guinea-pig kind ; it has the 
general characters of the rat tribe; and the voice 
and hair of the hog. It is about the fize of a 
hare; and in figure fomewhat refembles a young 
pig, to which it alfo approaches in it's voice and 
manner of eating. But, of all other animals, it 
bears the ftrongeft fimilitude to the agouti : like 
that animal, it is covered rather with coarfe hair 
than a downy fur; but then it is beautifully marked 
along the fides with fmall aih-coloured fpots, on 
an amber ground; whereas the agouti is nearly 
of one reddifh unvarying colour. The Paca is 
iikewife thicker and more corpulent than the 
agouti; it's nofe isfhorter; and it's hind-feet have 
five toes, whereas the latter has but three. In 
other refpefts the Paca bears fome diftant refem- 
blance to the rabbit: the ears are naked, and 
fomewhat ftiarp; the lovv^er jaw is a little longer 
than the upper; and the teeth are like thofe of a 
rabbit. It has Iikewife a ftiort tail, but not tufted ; 
and the hinder legs are longer than the fore. It 
alfo burrows in the ground like that animal ; and, 
from this fimilitude, it has fometim.es, though im- 
. properly, been denominated the American rabbit. 
The Paca does not ufe it's fore-paws, like the 
fquirrel or the agouti, to carry it's food to it's 
Vol. IL 
mouth; but hunts for it on the ground, and roots 
like a hog. It generally frequents the banks of 
rivers in the warm and moift climates of South 
America, where alone it is found. It becomes 
very flefliy; and, being drefiTed like a young pig, 
is confidered as a peculiar delicacy. 
Like the agouti, the Paca defends itfelf to the 
laft extremity ; and is very feldom taken alive. It 
is perfecuted not only by man, but by every beaft 
and bird of prey, which are all obfervant of it's 
motions ; and, if it ventures at any diftance from 
it's hole, are fureto feize it. 
But though the race of thefe little animals is 
thus continually deftroyed, they find fome refuge 
in their holes from the general combination; and 
multiply in fuch prodigious numbers, that the de- 
vaftation is fcarcely perceptible. 
A variety of this animal, of a beautiful white 
colour, is found on the banks of the River St. 
Francis. 
PACAMO. A long-bodied fifii of the muftela 
kind, commonly caught among fuch rocks as line 
the fhorcs. It is ufually about nine inches long, 
grovv'ing narrower and fmaller towards the tail : tlic 
head is large, broad, and thick; the mouth is 
fhaped like a crefcent; and it has very folid, but 
blunt teeth, 
2 PACC5; 
