BOTANY. 
bursts longitudinally, and is more or less 
remote from the flower, as in the snow-drop, 
narcissus, and arum. 5. Gluma, a huslc, is 
the peculiar chaffy calyx of grasses and their 
allies ; to it belongs the arista or awn, which 
however is not constant fn the same species 
of grass or corn : an elegant feathery awn is 
seen in the stipa pennata, feather-grass. 6. 
Pericheetium , a scaly sheath, investing the 
fruit-stalk in some mosses, as hypnum. 7. 
Vulva, the wrapper of the Fungus tribe, is 
either of a membranous kind sheltering 
their fructification, as in tire common mush- 
room, or more coriaceous, investing the 
base of their stalk as in many tungi. 
2. Corolla, fig. 36, the delicate, generally 
coloured, leaves of a flower, is always situ- 
ated within the calyx when both are present. 
This term comprehends both the petal, 
petalum, and the nectary, neetarium. A 
flower consists of one petal, or of several, 
the former denominated monopetalous is 
either campanulate, funnel-shaped, salver- 
shaped, wheel-shaped, ringent like the 
mouth of an animal, or personate, closed by 
a palate. Its parts are the tube and the 
limb. A polypelalous corolla is either cru- 
ciform, as in a wall-flower, rosaceous, papi- 
lionaceous, as in the pea kind, or incom- 
plete, when some parts are found in analo- 
gous flowers are wanting. The parts of a 
polypetalous corolla are the claw and the 
border. The great point to be considered 
with respect to the corolla in general is, 
whether it be regular or irregular ; in some 
flowers, however, it varies in the same 
species from one shape to the other, witness 
the genera antirrhinum and bignonia. 
Neither the calyx nor corolla is indispen- 
sably necessary to a flower. Both are want- 
ing in hippuris, and one or other is deficient 
in many genera. Hence botanists are led 
into a perplexity how, in some cases, to de- 
nominate the part which is present. When 
its green colour and thick texture agree 
with the generality of flower-cups, we do 
not hesitate to esteem it such ; but a calyx 
is often beautifully coloured, and there is 
some doubt whether the splendid leaves of 
tulips and lilies be not a true calyx ; at least 
they answer to the Linnaean definition, that 
their parts are opposite to the stamens, 
whereas those of a corolla should be alter- 
nate with the latter. The Linnaean hypo- 
thesis, however, though sanctioned by Jus- 
sieu, of the corolla proceeding from the 
inner bark, and the calyx from the outer, is 
entirely subverted by recent and more cor- 
rect observations on vegetable physiology. 
The functions of these two parts are per- 
haps, though similar, not exactly analogous. 
Those of the calyx probably resemble what 
are performed by the leaves, and this part is 
presumed by Dr. Smith even to secrete 
woody matter for strengthening the fruit- 
stalk. The corolla, indeed, seems destined 
to answer some exclusive purpose to the 
essential organs of impregnation with regard 
to air and light. It fades when they wither, 
and is altogether of temporary duration. 
Neetarium, the nectary, fig. 37, is frequent- 
ly a part of, or an appendage to the corolla ; 
sometimes the petal itself secretes honey ; 
sometimes a set of glands perform this func- 
tion ; and in other cases there is a peculiar 
petal-like apparatus for preparing or holding 
the nectarious juice. Linnaeus has remark- 
ed that plants whose nectary is distinct 
from the petals are commonly poisonous, 
which in general holds good with those of 
the more elaborate nectaries. A German 
writer, named Sprengel, has proved the 
corolla to be in many instances an attrac- 
tion as well as accommodation for insects 
in their sear ch after honey : he remarks cer- 
tain spots, called by him maculae Indicantes, 
which he conceives are designed to direct 
these little animals to their prey. The scent 
of flowers may perhaps contribute to the 
same end. There can be no doubt that the 
use of the honey is to attract insects, to 
promote the impregnation of the flower, 
and not, as some have thought, for the nou- 
rishment of the seeds or other organs, being 
frequently quite out of the reach of both. 
3. Stamina, fig. 38, the stamens, are situat- 
ed withinside of the corolla, and are various 
in number in different flowers, from one to 
several hundreds. These are the essentia! 
organs of impregnation. A stamen usually 
consists of two parts, filamentum , the fila- 
ment, and anthera, the anther, the latter 
of which only is essential. Its most com- 
mon shape is oblong, composed of two cells 
or cavities, which burst by a longitudinal 
fissure on the outside. A more unusual struc- 
ture is when the anther opens by pores to- 
wards the summit, as in the genus erica, or 
heath, of which such a profusion of beautiful 
species from the Cape of Good Hope enriches 
our green-liouses. Some of their anthers, 
moreover, are furnished with variously form- 
ed and very elegant crests and spurs, which 
afford the botanist marks for discriminating 
the species. The genus of firs, Pinus, has 
a jagged crest to its anthers, which serves 
also to distinguish some of the difficult spe- 
cies from each other. The situation of an- 
