plants, and are even discoverable in many 
without the help of glasses ; for upon break- 
ing the stalk or chief fibres of a leaf, the 
likeness of a fine woolly substance, or 
rather of curious small cobwebs, may be seen 
to hang at both the broken ends. This is 
taken notice of not only in some few plants, 
as in scabious, where it is more visible ; but 
may also be seen more or less in most others, 
if the leaves be very tenderly broken. This 
wool is really a skein of air-vessels, or rather 
of the fibres of the air-vessels, loosed from 
their spiral position, and so drawn out in 
length. 
AIRA, hair-grass, in botany, a genus of 
the Triandria Digynia class and order, and 
of the natural order of Grasses. There are 
twenty-five species, some of which have 
awns and others have none. The A. aqua- 
tica, water' hair-grass, generally grows in the 
margin of pools and watery places, running 
into the water to a considerable distance, 
and is known by the purple or bluish 
colour of the panicles, and sweet taste of 
the flowers. It is a perennial, and flowers 
in May and June. To this grass has been 
attributed the sweetness of Cottenham 
cheese, and the fineness of Cambridge but- 
ter. The A. crespitosa, or turfy-hair grass, 
grows in moist meadows and woods, is pe- 
rennial, it flowers in June and July, some- 
times trailing on the ground to the length 
of several feet, and the panicle exhibiting a 
beautiful silky appearance : cows, goats, and 
swine eat it, but horses are not fond of it. 
It is the roughest and coarsest grass that 
grows in pastures or meadows, and is called 
by the common people hassocks, rough-caps, 
and bull’s faces. To get rid of it, the land 
should be first drained, and the tufts of the 
noxious weeds pared off and burnt. The 
ashes yield a good manure. The A. 
flexuosa, or waved mountain grass, is the 
principal grass on Banstead Downs, and. the 
Mendip Hills. It is difficult of cultivation. 
AITONIA, in botany, so called from Mr. 
Aiton, his Majesty’s late gardener at Rew, 
a genus of the Monadelphia Octandria class 
and order, and of the natural order of 
Columniferae. There is but one species, 
viz. A. capensis, found at the Cape of 
Thunberg. It has a shrubby stalk six feet 
high, and a fruit resembling that of the win- 
ter cherry. With us it is of slow growth, 
and seldom exceeds three feet in height. 
At a sufficient age it produces flowers and 
fruit through the greatest part of the year. 
AJUGA, bugle, in botany, a genus of the 
TDidynamia Gymnospermia class of plants : 
he flower is monopetalous and ringent ; the 
upper lip being small and bifid ; the lower 
one large and trifid: there is no pericar- 
pium : the seeds are contained in the cup 
of the flower, and are four in number. There 
are 30 species. 
AIZOON, in botany, a genus of the Po- 
lyandria Pentagynia: the calyx is a one- 
leafed perianthium ; no corolla ; the stamina 
have many capillary filaments ; the anthers 
are simple, the pistillum has a five-cornered 
germ, the seeds are several : there are ten 
species, all belonging to the hot climates. 
ALA, in botany, is used in different senses ; 
sometimes it denotes the hollow between 
the stalk of a plant and the leaves ; some- 
times it is applied to the two side petals of 
the papilionaceous flowers, the upper petal 
being called the vexillum, and the lower one 
the carina; others use it for the slender 
membranaceous parts of some seeds, thence 
said to be alated ; and others, again, for the 
membranaceous expansions found on tire 
stems of plants, thence denominated alated 
stalks. 
ALABASTER, a well known description 
of stone used by statuaries and others. It 
is the sulphate of lime. See Chemistry and 
Mineralogy. 
ALi£, in anatomy, is sometimes used for 
the lobes of the liver, the nymphae of the 
female pudendum, the two cartilages which 
form the nostril, the arm-pits, young stems 
or branches, &c. 
ALANGIUM, in botany, a genus of the 
Decandria Monogyria class and order; the 
characters of which are, that it has from 6 
to 10 linear petals, from 30 to 32 stamina; 
the calyx dentated ; the fruit a spherical ber- 
ry, single-celled, containing from one to 
three seeds : there is only one species, viz. 
A. pungens. 
ALATED in botany, an epithet applied 
to the seed, stem, or leaf-stalk; a seed is 
alated, when it has an ala or membrane af- 
fixed to it, which, by its flying, serves to dis- 
perse it. The foot stalk of a leaf is alated, 
when it spreads out the sides. Alated leaves 
are those made up of several pinnated ones. 
ALAUDA, lark, in ornithology, a genus 
of birds of the order of Passeres ; the cha- 
racters of which are, that the beak is cylin- 
drical, subulate, and straight, bending to- 
wards the point, the mandibles are of equal 
size and opening downwards at their base ; 
the tongue is bifid; and the hinder claw is 
straighter and longer than the toe. Pen- 
nant adds, that the nostrils are covered with 
feathers or bristles, and the toes divided to 
their origin. There are 33 species, but we 
shall notice only two of them. 1. A, arven- 
