49 4 
M Y T 
the flidl; this, in fig. a, is fhown at BE of its natural 
iize. In fig. i, F, G, H, I, K, are feen the ramifications 
or branches, or rather a fmall part of them; and at 
I M is ill own one of the Ihort ligaments, with its mem¬ 
brane N O P. The ligament here appears on the upper 
fide of the membrane, in like manner as if the latter were 
fixed to fome other fliell; and here are to be feen the 
many parts whereby the ligament is joined to the mem¬ 
brane, which latter alfo appears fomewhat elevated at the 
place of joining. At Q R is reprefented another liga¬ 
ment; and at S T V its membrane, with the concave part 
of it appearing open, being in a contrary pofition to the 
former reprefentation. I have often feen this cavity reach 
into the ligament as far as M or R, but otherwife it is 
quite clofe and com^aft. Each of thefe ligaments confifts 
of a great number of exceflively-fmall particles, which 
cannot be contemplated without the greateft admiration, 
el'pecially when w-e recoiled the power which the mufcle 
has of moving each of thefe ligaments, and alio that the 
membrane mull be placed quite fmooth and flat upon the 
fliell, to which it is fixed, in order to caufe it firmly to 
adhere thereto. Now, if we farther confider that mufcles, 
while in the fea, always lie with that fliell upwards which 
they open occasionally, and that their (hells (which are 
very thin) and their bodies together are but little hea¬ 
vier than the water wherein they live, and alfo that many 
of them at low ebb-tides are left deftitute of water, at 
which times, in my opinion, much air mult infinuate 
itfelf betw'een their (hells, by which means they become 
lighter than the water ; they would then be liable either 
with the ebb to be carried out into the deep, or by the 
flood to be thrown upon the land, and fo would perilh. 
But provident Nature has taken care to preferve them in 
this refped, by furnifliing them with a ligament, fpread- 
ing into various branches, and at the end of each branch 
an organ, which I have named a membrane, by the help of 
which the mufcles can fix themlelves either to empty (hells, 
or other fubftances, or to one another, by which means 
they are preferved. 
“ But, as my principal defign was to difeover, as far as 
poflible, the generation or procreation of thefe fid), I come 
now’ to that part of the fubjeft. I obferved that thefe 
mufcles, fome in a greater and others in a lefs degree, 
had the outfides of their (hells covered with a kind of 
fubftance, thinly fpread upon the (hell, and firmly ad¬ 
hering to it, or rather to the membrane which covered 
it. Obferving this by the microfcope, I faw' that the par¬ 
ticles of which it confided, were all of a fimilarform, and 
alfo placed fide by fide, in regular order, and the mem¬ 
branes or (kins of thefe particles, as it were, united, or 
clofely joined together. I feparated a part of this fub¬ 
ftance from the lhell; and, placing it before the micro- 
fcope, I found that all the regularly-difpofed particles 
were much longer than they were broad; alfo that one of 
their edges was roundilh and thick, the other terminat¬ 
ing in a point or edge; and moreover that in many of 
them one fide was rifing, and the other flat; in a word, 
many of thefe particles, in lhape, w'ere very like a mufcle; 
and I not only thought that they were the eggs or fpawn 
of the mufcle, but I, alfo obferved that, when I broke the 
ftrong membranes inclofing them, feveral of the eggs, 
which were in lhape like a mufcle, appeared lying iingiy 
and feparately on the outfide of that membrane; and, 
when I feparated thefe unformed mufcles fingly, one 
from another, I imagined that I could fee the membranes 
or tendons of which they were compofed. I alfo faw the 
(hells, membranes, or coverings, of feveral eggs which 
were empty, and which I faw, or, more properly lpeaking, 
imagined, to be barren eggs. In other parts of this fub¬ 
ftance I faw eggs wherein I concluded that there were 
unformed mufcles, which conclufion I gathered from the 
multitude of veflels which I faw, which velfels conltituted 
the lhape or figure of a mufcle. Thefe eggs were not 
larger than a grain of common fcowering-fand. More- 
»ver I obferved, that the fmall or taper ends of the (hells 
I L U S. 
were feldom or never covered with the fpawn or eggs* 
the reafon of which I took to be, that, at the time^the 
mufcles emit their fpawn, they lie with the flat and broad 
part, as fhown_at fig. 2, A, B, C, D, uppermoft, and that 
part marked with the letter A next the ground, or bot¬ 
tom ; for I have often obferved, that, when mulcles have 
been cleaned and put into a veflel of water, and a hand¬ 
ful of fait thrown upon them, many will be foon found 
placed in the pofition I have mentioned ; and, while they 
lie in this pofition, and the eggs are put forth from the 
part marked C D, there mull: neceflarily be more eggs 
lodged near that fpot than towards the farther end° of 
the lhell. 
“ Several of thefe mufcles I placed in my ftudy, in two 
glades of water, with fome fait fprinkled on them, in 
order to examine them daily, and fee the progrels of 
growth in the young ones; and, upon this occafion, S 
could not fufficiently admire the exact and regular order 
in which the eggs were in many places difpofed, juft as if 
they had been fo placed by men’s hands; and from hence 
I was convinced that mufcles do not, like many other 
fillies, lay their eggs promifcuoully, but that they mull 
be furnilhed with fome kind of organ which they can 
projedt beyond the lhell, and with it difpofe them fo 
regularly. I have before laid, that I thought I faw a 
kind of finews or tendons in the eggs; and, upon further 
examination, I perceived fixteen of thefe tendons, like 
ftreaks, in the unformed mufcle, and among them I faw 
fome ftill fmaller ftreaks, from whence I concluded, that 
they were in fadt veflels to form the fubftance of the 
future (hell, for they lay all in one diredlion, that is, from 
the fmall end, fpreading or diverging round about; and 
they were thickeft at that part, and thinned at the ex¬ 
tremities, fpreading wider towards the broad and thin 
end of the lhell. I caufed a drawing to be made of a few 
of the eggs, in the order they lay on the parent lhell, and 
as they appeared through the microfcope: this is (hown 
at fig. 3, repreienting fix of them, in fome of which it 
may be feen that one fide is more curved than the other, 
and in which eggs may alio be feen the finews,.veflels, or 
ftreaks, I have mentioned. 
“ Upon confidering that the lobfter and the Ihrimp 
carry their eggs about them until the young are perfedlly 
formed, it feems probable to me, that this is alfo the cafe 
with the mufcle; lor, ather.wife, how could this ipecies of 
lilh be propagated ? el’pecially if we confider that they lay 
their eggs in the middle of winter, and generally in (hallow 
waters, where the Chore is muddy; and, if the eggs were 
not depofited on the Jkel/s, they would be buried in the 
mud, with the common flux and reflux of the tide; not 
to mention that in ftormy weather'they would be carried 
out to fea; but, while they are fixed to the.(hells of the 
parent, and thefe laft adhering to folid fubftances on the 
Chore, the eggs are, by this means, in great numbers pre¬ 
ferved ; and thefe young mufcles, when come to fuch a. 
maturity as to be feparated from the (hells, may, in windy 
weather, ftrong tides or currents, be eafiiy carried to other 
muddy lhores on the coaft, in places where for many years 
before no mufcles were to be found. I have made a 
rough calculation of the number of thefe eggs, and I 
compute that there are frequently more than two thou- 
land fixed to the fliell of one mufcle ; in faft, I have feen 
mufcles, each of which I judged had more than three 
thoufand on it. I have before laid, that the eggs of muf¬ 
cles are the lize of common Icowering-fand ; but, as this 
is not of the fame fize in all countries, I compute that, 
to the belt of my judgment, feven of thefe eggs, in breadth, 
are equal to the fifteenth part ot an. inch, conlequently. 
the breadth of 105 eggs is equal to one inch ; and I allb 
compute, that 60 eggs, in length, make an inch ; therefore - 
a fquare inch will, contain 6,300 ; and, as each egg is no 
thicker than broad, ,105 of them mult lie one on another 
to make the thicknds of an inch ; the Cum total then of 
the eggs which will be contained within.theTpace of a 
cubic inch, is 661,5005 and hundreds of fuch eggs may 
