118 Vhe: MBYO PO. car sch 
inteftines, which were for that reafon made pro- 
portionably larger and longer in the young Frog, 
than even in the full grown one. On meafur- 
ing the length of the ‘iinteftines in this little crea- 
ture, I obferved it to be five inches. When I 
thoroughly ‘viewed the contents of the gullet, 
ftomach and {mall guts, I obferved they were all 
of the fame nature, and contained fome parts, of 
aquatic plants, little grains of fand, clay or mud. 
Therefore, when I fed thefe young Frogs with 
Duckweed for fome time in my chamber, in 
ftone bafons, I observed that they eat all the 
roots of it fo clean, that none remained ; but not 
the round little part or leaf, which is fall of air, 
and fwims on the furface of the water. But af- 
terwards, when they had nothing to eat under 
the water, I obferved them continually rolling 
about on their back for hunger, and conftantly 
catching the refidue of the Duckweed in their 
mouth, though it was too big for them to fwal- 
low. 
At the fame time, I obferved alfo, that the 
otbicular leaf of the Duckweed is not only full 
of air-bubbles, and for that reafon neceflarily 
floats on the furface of the water; but that even 
its very root of the plant, contains air, tho’ not 
in a proportiona] quantity: this is probably the 
reafon why the root fubfides. I further obferved, 
that the extremity of the peduncle, or root of 
the Duckweed, is thicker in proportion, and 
more porous than the ftalk itfelf: and confe- 
quently the nourifhment feemed to me to pene- 
trate through that extremity to the leaves, I 
likewife obferved, that when I nurfed up one 
plant of Dackweed in a bafon of water, and ex- 
pofed it to the rays of the fun, it infenfibly put 
forth many roots; nay, that the very leaf of 
thefe little: plants multiplied and increafed into 
two, three, or four other leaves; the leaft of 
which; afterwards feparating from the parent, 
formed feveral other fmall ones; fo that this 
little plant feemed to multiply itfelf without feed, 
in a very fhort time. I had indeed refolved, yet 
more accurately, to inveftigate and delineate thefe 
things: but the reafons before mentioned, have 
likewife diverted me from this refolution. 
Some years ago, examining the tubercles, 
which are found on the back of Fern-leaves, I 
obferved that they confifted of fome thin plates, 
or Jaming, in which the pods, containing the real 
feeds of the plant, were enclofed: though many 
authors deny that this, and fuch like {pecies of 
plants have any feed“, Since the art and ftruc- 
ture obfervable in thefe pods is admirable, I thall 
* Every part of natural hiftory is greatly improved of late time. 
INS a I). ike FR oor: 
give a brief defcription of them, until I have 
time to delineate them magnified ; as { have fore 
metly done to oblige Dr. Arnold Syen, profeflor 
of botany, to whom I freely communicated this 
uncommon obfervation, fince it regarded his 
profefiion: of which, however, no further no- 
tice need be taken here. 
Thofe pods are of a round figure, and are 
compofed, as it were, of two hemifpheres, 
placed clofe to each other; but they may be 
parted in the middle. About this joint or feam 
is beautifully twifted a little herbaceous cord, 
which keeps the two fegments of the pod in 
their fituation. One extremity or bafis of this 
little rope grows to the fern-leaf; but the other 
is affixed to the lower hemifphere of the pod ; 
and at length, after furrounding the whole pod, 
it terminates in the upper part of it. 
In the cavity of this pod the Fern-feed lies, 
and it is indeed {fo fmall, that it is with great 
difficulty to be difcerned by the naked eye; 
and when blown upon, it vanifhes into the air 
like fine duft. 
But this is only a fmall part of thofe beauties 
that are obferved about the pod, and its cord. 
I beg leave to obferve from hence, that when 
the feed grows ripe on the infide, and the pod 
dries away, then the cord, twifted round the 
pod like a rope, is fo ftrongly curled, on ac- 
count of its contorfions, that it makes the ped 
fly into two parts, and forces a paflage for the 
feed to difperfe itfelf. 
This may be feen clearly and diftin@ly, if 
the feed be examined in autumn with a micro- 
{cope: for as the head is, under this infpeétion, 
very near this feed, I have often obferved, that 
a great number of thefe pods, burft afunder 
by force of the twifted cords, which are con- 
tracted by the breath and heat of the body, 
and the feed,, is by this means thrown out. 
But thefe things are only faid occafionally in 
this place -+-. 
The pancreas in the Tadpole was obferved, 
Tab. XLIX. Fig. 1. p, to be fituated near the 
ftomach, and compofed of diftinétly confpi- 
cuous glandules. Below the ftomach appeared 
g the {mall gut, with its blood-veffels and con- 
tents, which were of a greenith ‘tran{parent 
colour. But the convolutions of the inteftines 
exhibited the moft beautiful fight of all; for 
thefe were orderly and regularly rolled rr into 
two diftin& ferpentine forms. One of their 
extremities was joined to the rectum, s, which 
at length conftituted the ‘fundament between 
This author firft difcovered the feeds of Fern, unknown to for- 
mer writers: and we have fince difcovered thofe of Duckweed, which were unknown to him. ‘This little plant 1s now known to 
produce its likein the manner of all others. Small as the whole plant is, it produces flowers of all kinds from the fame root. In 
{ome of them are the filaments, two in number, and a fingle ftyle rifing from,a {mall oval rudiment of a fruit: im others, there are 
no filaments, but only the rudiment of a fruit with its flyle.. ‘! he cap which contains thefe, is alike in both kinds; it is rounded,, 
and {plits on one fide: there are no petals in either flower. "The rudiment of. a fruit decays, and comes to nothing in thofe flowers” 
which have the filaments with it; but in the others it becomes a globous feed veffel, terminated by a point, and contains feveral ob- 
long feeds, ‘This is -eftablifhed on the opinions of Micheli, Dillenius and.Buxbaum, and is confirmed by Linnzus, and by expe- 
rience. a i eae : arteee 
+ The world owes/great acknowledgments to this author for many difcoveries ; and he with jaftice claims that diflin@ion, in 
regard to the feeds of ern, of which he treats more largely hereafter. The fcience of Botany is fo far improved fince his time, 
that we have difcovered diitin@lly the feeds, and their peculiar diftribution on the leaves, in all the capillary plants. In Ofmund they 
are. enclofed in diftingt lobular capfiles, which burft fideways; in the Louchilis they are laid -in lines, like crefcents, under the 
hollows of the leaves; in Hartftongue‘and Trichomanes they are difpofed, in ftraight lines, under the difk of the leaf; in Polypody 
they are arranged in round dots; in the true Maidenhair in oval affemblages, at the t ps of the leaves: the Horfetail has them in 
oval pikes; and the Adderftongue in cells, placed in two rows along the {pixe. ‘Thefe plants are now found to belong diftingily 
6 the four kinds; and in the Rutta Muraria they cover the whole under-part of the leaf, 
the 
