SPINE. 
and are perforated by a canal or prolonged an- 
nular opening in which is lodged the spinal 
marrow or great nervous medullary cord. The 
combination of strength and mobility, of bone 
and muscle, of circulatory vessels and nervous 
processes, of earthy matter and cartilage and 
flesh and fluid, of the most diversified and mighty 
functional powers in the structure of the spine, 
viewed both in itself and in its connexions with 
the entire organization of the body, constitute a 
perfect museum of wonders, and afford multi- 
tudinous and overwhelming displays of the wis- 
dom and goodness of the Creator, and present a 
brilliant field of study to at once the anatomist, 
the physiologist, the moralist, and the physico- 
theologian. Fracture of the horse’s spine some- 
times occurs in leaping a ditch, in struggling 
during a painful operation, or on other occasions 
of sudden and severe contortion; and it is always 
fatal. 
SPINE. A sharp, indurated, terminating point 
in the leaf or calyx of a plant. It is well exem- 
plified in the piercing armature of the thistles. 
Some spines are mere processes from the angles 
or apexes of leaves; and others, as in the com- 
mon furze, may be regarded as comprising the 
whole bulk and substance of the leaves. Prickles 
and thorns differ from spines in their constitu- 
ting an armature of the stems and branches of 
plants; and prickles issue merely from the bark, 
and are stripped off along with it, while thorns 
issue from the wood, and occur only on ligneous 
plants, and may be regarded as abortive and in- 
durated buds. 
SPIRAIA. A genus of ornamental plants, of 
the rosaceous order. Three species grow wild 
in Britain; and upwards of forty have been in- 
troduced from other countries, principally North 
America, Siberia, and Eastern Europe. A few 
are hardy, perennial-rooted herbs, propagable by 
division of the plant; and all the rest are hardy 
deciduous shrubs, varying in height from 14 to 
8 feet, and propagable in some instances from 
layers, and in others from suckers. A few have 
red or pink flowers; and nearly all the rest have 
white flowers. Two of the indigenous species 
are noticed in the articles Mzapow-SweeT and 
Dropwort; and one of the introduced species, 
in the article Goats’-BEARD. 
The willow-leaved species, or common spirea, or 
spireea frutex, S. salicifolia, occurs wild in some 
of the woods of Britain, but has been introduced, 
in several varieties, from Russia and Tartary, and 
ranks as an ornamental plant in gardens and 
pleasure-grounds. It is a deciduous shrub, of 
commonly about 5 or 6 feet in height. The root is 
spreading, and sends up a profusion of stems and 
suckers. The old stems are branching; and the 
suckers of a single season’s growth are as high 
in autumn as any of the stems. The bark of all 
is smooth; that of the old stems is red, though 
for the most part clouded with a dusky matter ;_ 
that of the shoots from the stems is lighter yet 
SPIRAUA. 
311 
reddish; and that of the suckers from the root 
is white. The leaves grow without order on 
the branches, and have a fine green colour, and 
are spear-shaped, obtuse, naked, and serrated. 
The earliest flowers are produced in June, at the 
ends of the branches which grow from the main 
stem; and before these cease to bloom, flower 
buds appear at the ends of the suckers, and 
are generally larger and fairer than those of the 
stems, and often keep up a succession of bloom 
till late in autumn. The flowers are produced 
in double branching-spikes, which are broadest 
toward the base, and diminish gradually up- 
ward, and end obtusely at the top; and they 
are of a pink or pale red colour; and, though in- 
dividually small, yet, in consequence of being 
agoregated in these thick spikes of 4 or 5 inches 
in length, they have a good appearance. Five 
varieties of this species occur in collections,— 
the white, the alpine, and the broad-leaved, all 
with white flowers, —the large - flowered, with 
pink flowers,—and the flesh-coloured, with car- 
mine flowers. 
The tomentose or downy spirza, S. tomentosa, 
is a native of North America, and was introduced 
to Britain in 1736. It is a deciduous shrub of 
about 5 feet in height: Its stems possess a con- 
siderable degree of downiness; its branches are 
covered with a purple bark; its leaves grow 
irregularly on the branches, and are ovate-lance- 
olate, unequally serrated, fine green above, and 
downy below; and its flowers grow in double 
branching spikes at the ends of the branches, 
and have a bright pink or red colour, and bloom 
from July till September, and make a fine ap- 
pearance. 
The hypericum-leaved spirea, or hypericum 
frutex, S. hypericifolia, is a native of Canada, 
and was introduced to Britain in 1640. Itisa 
deciduous shrub of five or six feet in height; 
and it has great beauty and elegance,—not so 
much from its natural form of growth, or from 
the colour of the bark or leaves, as from the 
flowers; for the branches are produced irregu- 
larly. The older shoots are covered with a dark 
brown bark; the younger shoots are smooth and 
lighter, and are tinged with red. ‘The leaves 
are small, though of a pleasing dark green colour, 
and they come out irregularly and are entire. 
The flowers are produced in May, almost the 
whole length of the branches, and are of a white 
colour; and though separately small, they are 
collected in umbels which sit close to the branches, 
and ornament their whole length, so that scarcely 
anything but flowers, and the main stalks, are 
to be seen. The shrub, in fact, has the appear- 
ance of one continued flower, branched out into 
as many different divisions as there are twigs,— 
every twig looking at a little distance like a 
long narrow spike of flowers; and these being 
all over the shrub and of a pure white, they 
make a delightful show. 
The sorbus-leaved spireea, S. sorbifolia, is a na- 
