| plant. 
| and Cambridgeshire. 
COW-WHEAT. 
892 
distillation, it disengages ammoniacal vapours in 
abundance.” He then states that the fatty mat- 
ter is analogous to bees’ wax, so that a kind of 
wax candles can be made of it; and adds that 
the liquid which remains after the fatty and the 
fibrinous matters are separated, is water holding 
in solution a free acid, a little sugar, and some 
saline substances,—and, that, on burning the 
milk, ashes were obtained consisting of phos- 
phate of lime, lime, magnesia, and silica. An 
attempt was commenced, about 20 years ago, to 
propagate and cultivate the cow-tree in the West 
Indies. 
COW-WHEAT,—botanically Velampyrum. A 
genus of annual weedy plants, of the figwort 
tribe. Their botanical name signifies ‘black 
wheat,’ and alludes to the black and wheat-like 
appearance of their seeds; and their popular 
name implies that these seeds might probably be 
cultivated as food for cattle, or alludes to the 
fact that cows and oxen greedily eat the entire 
Four species are indigenous as weeds in 
Britain; and a fifth species, of a sort of orna- 
mental character, was long ago introduced from 
continental Hurope. All are about 20 inches 
high, and bloom in July, and have yellow-col- 
oured, tubulous, four-segmented flowers. The 
broad-leaved or common meadow species has the 
floral footstalks standing at a distance; and it 
grows wild in the woods cf many parts of Bri- 
tain. The narrow-leaved species has quadrangu- 
lar spikes, and grows plentifully in Bedfordshire 
The species with blue tops 
occurs sparsely in some of the sandy lands of 
Norfolk, and is an abundant corn-weed in Flan- 
ders and West Friesland. This last species has 
been accused of damaging bread and producing 
deleterious effects in the same manner as darnel; 
yet is said to be delicious food for cattle, and was 
formerly proposed for cultivation as fodder. 
CRAB. This name—which appears to be de- 
rived from the Latin carabus, used by Pliny to 
designate certain crustaceous species—is now 
applied to a considerable group of invertebral 
animals, whose bodies are covered by an external 
skeleton, or calcareous crust, having ten articu- 
lated limbs, adapted for swimming or walking, 
and breathing by branchie or gills, The head 
and corselet are united, the latter being broader 
than it is long. The tail is short in proportion, 
and concealed by being turned forward beneath 
the body. This genus is distinguished from all 
others of the same family by the semicircular 
shape of the corselet, the pointed or hooked ex- 
tremities of the last joint of the limbs, the nar- 
rowness of the superior shell from before back- 
wards, the posterior direction of the hinder tarsi, 
and the absence of spines or ridges from the for- 
ceps, or biting claws. They belong to the fourth 
section of ten-legged, short-tailed crustacea, De- 
capoda brachyura, of the latest systems, and are 
of numerous species, exceedingly various in size, 
colour, and modes of living. A slight survey of 
| considerable size. 
Ae heesce a BA 
CRADLE. 
the structure of these animals might lead to the 
opinion that their senses were limited or imper- 
fect; but proper observation shows the contrary 
to be true. The sense of sight, in most of the 
species, is peculiarly acute, and enables them to 
distinguish the approach of objects from a very 
considerable distance. Their power of smelling 
is also great, though we have not yet discovered 
the organ by which this sense operates. It has 
been inferred that the antennz serve this pur- 
pose. Until more positive knowledge is acquired 
on the subject, no evil can arise from this opin- 
ion as to the seat of the sense of smell. The en- 
trance to the organ of hearing is at the base of 
the peduncle sustaining the antenne, and con- 
sists of a small, hard, triangular prominence, 
covered by a membrane, within which is a cavity 
containing the expanded auditory nerve. Of all 
the senses, that of touch, except so far as it may 
be possessed by the antenne, appears to be the 
least perfect, since the whole body and limbs are 
incrusted with a hard, compact shell. Of the 
sense of taste, we can say nothing, but that, as 
the animals possess a remarkably complex and 
elaborate apparatus for mastication, there is no 
reason for believing them devoid of this sense. 
The mouth is furnished with at least eight pieces 
or pairs of jaws, which pass the food through an 
extremely short gullet into a membranous sto- 
mach of considerable size. This stomach is ren- 
dered curious by having within certain cartila- 
ginous appendages, to which strong grinding 
teeth are attached. These, in crabs, are five in 
number, and placed at the pyloric extremity, or 
outlet of the stomach; so that the aliment, after 
being subjected to the action of the jaws, is again 
more perfectly chewed by the stomach-teeth, be- 
fore entering the digestive tube, where it is ex- 
posed to the action of the biliary fluid of the 
liver. The latter organ is of great size in these 
creatures, and is all that soft, rich, yellow sub- 
stance, found immediately beneath the superior 
shell, usually called the fat of the crab, and justly 
esteemed a delicious morsel. A little posterior 
to the stomach (commonly called sandbag), the 
heart is situated—a somewhat globular, whit- 
ish body, which propels a colourless lymph 
to the gills and rest of the body, whence it is 
brought back to the heart by a hollow vein of 
The process of sloughing, 
moulting, or throwing off the entire calcareous 
covering, which constitutes their only skeleton, 
is common to all the crustacea, and is toy wor- 
thy of attention. 
CRAB-TREE. See Apprz-Trex and Phare 
CRACCA. See Vetcu. 
CRACKS. Soreness in the heels of horses. 
Ordinary forms of it are often occasioned by want 
of care and of cleanliness; and a virulent form of 
it sometimes attends grease. See the article 
GREASE. 
CRADLE. A wooden necklace for a horse. It 
consists of a string of round pieces of wood; and 
eT nn aa a —«SIi2320 III III III 
