POL 
some parts of India denominated the royal 
fish, from its extraordinary excellence. The 
application of the epithets, royal and ple- 
beian, to the same animal, constitutes a cu- 
rious coincidence : the former probably re- 
fers to the plainness of its appearance, and 
the other to its exquisiteness for food. 
P. niloticus, is both in form and taste su- 
perior to every other fish in the rivers 
which flow into the Mediterranean or At- 
lantic seas. It is covered with scales, re- 
sembling the most brilliant silver spangles, 
and is of the weight of thirty, in some in- 
stances, of seventy pounds. It is a native 
of the Nile, and Mr. Bruce has minutely 
detailed the process adopted by the Egyp- 
tians for taking it, by a cake of flour, dates, 
and other ingredients, with a considerable 
number of hooks concealed in it; but at- 
tached to a string held by the fisherman, 
w'ho floats on the stream, upon a blown-up 
goat’s skin, in order to sink this mass, and 
then returns to , the barlk. He then fixes 
the line to some tree, connecting it with a 
bell, the sounds of which give him notice of 
the success of his experiment, being pro- 
duced by the twitchings and pulls of the 
fish. 
POLYPE, or Poi.vpus, in zoology, a 
small fresh-water insect of a cylindric fi- 
gure, but variable, with very long tentacu- 
la. See Hydra, 
POLYPODIUM, in botany, a genus of 
the Cryptogamia Filices class and order. 
Natural order of Filices, or Ferns. Gene- 
ric character : capsules distributed in 
roundish dots, on the back or lower surface 
of the frond. There are one hundred and 
thirty-seven species ; most of these are of 
American growth, and very little known in 
Europe, except from dried specimens, not 
always collected with judgment enough to 
show satisfactorily the true characters of 
the fronds and fructification. 
POLYPREMIUM, in botany, a genus 
of the Tetrandria Monogynia class and or- 
der. Natural order of Caryophyllei. 8cro- 
phularise, Jussieu. Essential character : ca- 
lyx four-leaved ; corolla four-cleft ; whgeb 
shaped, with obcordate lobes ; capsule 
compressed, emarginate, two-celled. There 
is but one species, viz. P. procumbens, a 
native of Carolina and Virginia. 
POLYTRICHUM, in botany, a genus of 
the Cryptogamia Musci class and order. 
Natural order of Musci or Mosses. Essen- 
tial character: capsule lidded, on a very 
small apophysis or receptacle; capsule, 
villose. There are nineteen species, chiefly 
POM 
natives of th6 north-west coast of North 
America. 
POMACE®, in botany, the name of the 
thirty-sixth order in Linnaeus’s Fragments 
of a Natural Method, consisting of genera, 
which have a pulpj' esculent fruit, of the 
apple, berry, and cherry kind ; such are the 
primus, pyrus, ribes, &c. The plants of 
this order are most of the shrub and tree 
kind : the roots are branched, fibrous, and 
long. In the drop-wort tliey consist of a 
number of , oval knobs, v\hichhang, or are 
fastened together by slender fibres : hence, 
its English name, and also the Linnaean 
name spiraea .filipendula. The stems and 
branches are cylindric ; the bark is thick 
and wrinkledl The buds are of a conical 
form, placed in the angles of the leaves, 
and covered with scales which lie over one 
another like tiles. In the apple, pear, 
plum, &c. besides the buds of the leaves, 
there are scaly buds or eyes of a difi'er- 
ent form from which proceed bundles or 
clusters of flowers. The leaves which differ 
in form, being in some genera simple, in 
others winged, are, in the greater number 
placed alternate. 'I’he flowers are univer- 
sally hermaphrodite, except in the spiraea 
aruncus, in which male and female flowers 
are produced upon distinct plants. The 
flower-cup is of one piece with five divisions 
which are permanent, and placed above 
the seed-bud, in the apple, currant, .&c. ; 
in others they fall off with the flower, or 
wither upon the stalk. The petals are five, 
inserted into the tube of the calyx. The 
stamina are generally twenty and upwards, 
attached also to the margin of the tube of 
the calyx, the anthers are short, and slight- 
ly attached to the filaments. The seed-bud 
is single ; and the seed-vessel is a pulpy fruit 
of the apple, berry, or cherry-kind. Those 
of the apple kind are divided internally into 
a number of cells. The seeds in the pome- 
granate, apple, and currant-trees, are nume- 
rous; in the service-tree three; in the med- 
lar five : in peach, plum, &c. a single nut 
or stone, containing a kernel. 
POMETIA, in botany, a genus of the 
Monoecia Hexandria class and order. Es- 
sential character: calyx, one-leafed, six- 
cleft ; petals six : male, stamens six : female, 
berry globular, with one seed in the centre. 
There are two species, viz. P. pinnata and 
P. ternata. 
POMMEREULLIA, in botany, so named 
in memory of Lady du Gage de Pomme- 
reull, agenus of the Triandria Monogynia 
class and order. Natural order of Gia- 
