426 
POPULAR SCIENCE REVIEW. 
down the slender tube into the ovule, and mingle with the 
fluid in the interior, the ovules are fertilized, and proceed 
gradually to become mature seeds, whilst the pollen tubes 
wither, as well as the style and stigma, their work having been 
accomplished. Such, in brief, with various modifications, is 
the mode of fertilization in the majority of plants. It may be 
added, that in their young state, the above essential or 
reproductive organs are enclosed and protected by one or two 
series of over-lapping leaves, and, when thus enclosed, we call 
the whole a flower hud. As the flower bud expands, the outer 
series of leaves, often of a green colour, and termed’the calyx, 
expands first, then the inner, or coloured series, which is the 
corolla. The number of leaves in the calyx and corolla is 
variable, according to the genus or species of the plant. Some- 
times both series are coloured, and sometimes only one series is 
present. These together constitute floral envelopes, which 
enclose and protect the reproductive organs during their young* 
and tender state. 
In Orchids the whole structure of the flower departs widely 
from this type, there are ^^reproductive organs, and also 
floral envelopes,^^ but how these difier from those of ordinary 
plants we will endeavour to explain. As we do so, let us hope 
that those who need no such explanation will bear with us 
patiently, for the benefit of readers who may not be so fortu- 
nate as themselves. 
About forty species of Orchids have a place in the British 
Flora, and the majority of these are lovers of chalky soils. In 
all there is one point of structure in which they agree. The 
filaments of the stamens, and the style which surmounts the 
ovary, are fused together into one thick column, which occupies 
the centre of the flower, so that there are no separate and dis- 
tinct stamens as in other plants. We shall best illustrate this 
by taking one common species as a type, and, for the present, 
confine our observations to that species. The Early Orchis 
{Orchis mascula) has a flower with six dmsions, arranged in 
two series ; the outer three correspond to the calyx, but, instead 
of being green, are coloured; the inner series, also of three 
parts, corresponds to the corolla, and each part may be called 
a petal ; these, of course, are coloured, and are placed alternately 
with the outer series. One of these petals, that is the lower 
one, is larger than the rest, and differs in shape ; in some species 
it is very large, and shaped almost like a slipper. This is the 
lahellum. This lower petal, or labellum, has a spur, or long 
pouch, which extends backwards, which, on account of its 
secreting nectar, so grateful to insects, is called the nectary. 
In fig. I, all the floral leaves have been removed, except the 
labellum [1) and its nectary {n). In fig. 2, a front view of the 
