ARC 
other parts of Germany, from the banks of 
the Wolga to India aud Persia, through Si- 
beria and Great Tartary to Kamschatka, 
and even the continent of America. It is 
not certain that these sleep in the winter 
like others of the Arctomys genus. They 
breed in the spring, and produce from five 
to eight at a time. They are said to be 
irrascible and quarrelsome among them- 
selves, and their bite is very severe. They 
feed not only on animal food, but on small 
birds and other animals, which they will 
kill. They are easily tamed, and will grow 
familiar in a few days. They are extremely 
clean, and after feeding, generally wash 
their faces, and clean their fur. Like other 
domestic animals, they are fond of being 
caressed, and will feed from the hand. 
Their sleep is profound during the whole 
night, and in cold and rainy weather 
through the greater part of the day. See 
Plate II. Mammalia, fig. 1, 2, and 5. 
ARCTOPUS, in botany, a genus of the 
Polygamia Dioecia class of plants, the ge- 
neral umbel of which is long nnd unequal ; 
the partial umbel is shorter ; the involucra 
consist of five leaves ; the corolla of five pe- 
tals ; the fruit is single and bilocular, and 
stands under the receptacle of the floscule ; 
the seed is single, cordated, and acumi- 
nated. There is but one species. 
ARCTOTHECA, in botany, a genus of 
the Syngenesia Necessaria : receptacle cel- 
lular and chaffy ; calyx imbricate. There 
is but one species. 
ARCTOTIS, in botany, a genus of the 
Syngenesia Necessaria class of plants, the 
common calyx of which is roundish and im- 
bricated ; the compound flower is radiated ; 
the hermaphrodite corollulse are tubulous 
and numerous in the disk : the proper her- 
maphrodite flowers are funnel-shaped ; 
there is no pericarpium ; the seed is single, 
roundish, and hairy. This genus is sepa- 
rated into the following divisions : A. recep- 
tacle villous, 31 species; B. receptacle 
chaffy, 11 species ; C. doubtful, 18 species. 
ARCTURUS, a fixed star of the first 
magnitude, in the skirt of Bootes : so called 
from the circumstance of its being near the 
tail of the Bear. It has been thought to 
be the nearest fixed star to our system visi- 
ble in the northern hemisphere, because the 
variation of its place, in consequence of a 
proper motion of its own, is more remark- 
able than that of any other of the stars, 
and by comparing a variety of obser- 
rations respecting the quantity and direc- 
tion of the motion of this star, he infers, 
ARD 
that the obliquity of the ecliptic decreases 
at the rate of 58" in 100 years, a quantity 
that nearly corresponds to the mean of the 
computations framed by the celebrated Eu- 
ler and Lalande, upon the more unerring 
principles of attraction. 
ARCTUS, in astronomy, the Greek name 
for the Ursa Major and Minor. 
ARDEA, in natural history, a genus of 
birds of the order Grallas. The characters 
of this genus are, a long, strong, sharp-point- 
ed bill; nostrils linear; tongue pointed; toes 
connected by a membrane as far as the first 
joint; the middle claw of some of the species, 
of which there are 79, pectinated. This 
genus is separated into five divisions, viz. 
A. crested ; bill hardly longer than the head ; 
B. cranes, bald ; C. storks, orbits naked ; D: 
herons, middle claw serrate inwardly ; E. 
bill gaping in the middle. 
Some ornithologists have separated the 
herons from the storks and cranes; others 
preferring the Linnaean system, class the 
whole under one genus, which according to 
Gmelin, consistis of nearly 100 species, 
though Latham enumerated but 79. They 
are widely distributed over various parts of 
the globe, differing in size, figure, and plu- 
mage, and with talents adapted to their 
various places of residence, or their peculiar 
pursuits. But notwithstanding the variety 
in their bills and plumage, the manners of 
all are nearly the same, so also is their cha- 
racter which is stigmatized with cowardice 
and rapacity, indolence and yet insatiable 
hunger; and it has been observed that from 
the meagre-looking form of their bodies one 
would suppose the greatest abundance al- 
most insufficient for their support. 
Ardea pavonia. This is as large as the 
common heron; the length two feet nine 
inches; the bill is two inches and a half 
long, straight, and of a brownish colour; 
irides grey ; the crown of the head covered 
with soft black feathers like velvet ; on the 
hind part is a tuft composed of hair, or 
rather bristles, arising near each other at 
the base, and spreading out on all sides in a 
globular form ; this is four inches in length, 
and of a reddish brown colour ; the sides of 
the head are bare of feathers, being covered 
only by a fleshy membrane, of a reddish 
colour at the lower part, and in shape not 
unlike a kidney ; on each side of the throat 
hangs a kind of wattle; the general colour 
of the bird bluish-ash ; the feathers on the 
fore part of the neck are very long, and 
hang over the breast ; wing coverts white ; 
the greater ones incline to rufous, and those 
