Vipers. REPTILES. Common Viper. 47 
developed much more than any of the others, elongating 
tliemselves into a point, and presenting exactly the 
appearance of a horn on each eyebrow. As Schlegel 
remarks, this anomaly in the organization of this ser- 
pent, more curious than of any real scientific value, has 
not failed to excite in the highest degree the admi- 
ration of mankind, and to occupy their imagination 
from the earliest periods of time to our own days. The 
Egyptians, of whose country this viper is a native, and 
who were fond of the marvellous, have accordingly 
frequently figured it in their hieroglyphical writings on 
their ancient monuments. It was pointed out by them 
to strangers as one of the most redoubtable of beings, 
and it was related of this formidable reptile, that in 
some remote period of antiquity an invasion of a host 
of them had actually depopulated a part of their country. 
The name of the genus, Cerastes, has been given to it 
from these horns, being derived from the Greek word 
keros (xssaj), a horn. These appendages, however, 
do not exist in all individuals, and perhaps are peculiar 
to the males ; though the want of them haS induced 
some naturalists to describe those in which they were 
absent as constituting a distinct species. 
THE CERASTES {Cerastes Hasselquistii ) — Plate 4, 
fig. 4 — resembles in general form our common viper, 
but its body is much thicker in the centre and less 
compressed. The back is somewhat keeled, and the 
(ail is slender, very short (only about a tenth of the 
whole length) and terminates in a very fine point. 
The head is very large, distinct from the bodyq and 
covered with scales of an irregular form, smaller than 
those of the trunk, and all keeled. In the males, one 
of these scales developes itself into a lengthened point 
two or three lines long, which rises immediately over 
the ey’cs on each side, and gives a resemblance to a 
small horn. They are furrowed throughout their whole 
length, and are very movable. Their uses, if they can 
be at all of use to the animal, are entirely unknown, 
but numerous conjectures and assertions have been 
made about their nature. . The eyes have a yellowish- 
green iris, and their pupil is narrow and vertical. The 
Cerastes is generally' of a very pale brown colour, or a 
pale yellow shading into grayish-brown, on the upper 
part of the body, with five or six rows of deeper spots of 
rather irregular shape and unequal size, but generally 
pretty regularly disposed. The under part of the body 
and throat are usually white. The tail is often black 
at the tip. The usual length of this species of serpent 
is about two feet, though Bruce says, it is only thirteen 
or fourteen inches. We are indebted to this traveller 
for many interesting particulars with regard to the 
Cerastes. It inhabits the vast, burning deserts of 
Northern Africa. Shunning humid and marshy situa- 
tions, it is found only in the hot, arid sands of Egypt, 
Syria, and Arabia. It lies all day in holes in the sand, 
and is found in close contiguity to the Jerboa, which 
lives in similar habitations, and which forms part of 
this reptile’s food. 
Genus Viper a. 
In the second group of the true Vipers, or those in 
which the head is more or less covered with large scales, 
plates, or shields, the genus Vipera is pre-eminent. 
There are three sjjecies natives of Europe, and all 
resembling each other in general appearance. They 
differ, however, in the arrangement of the plates, and 
in the shape of the head ; and according to some of the 
latest writers, have even been divided into two distinct 
genera. In form they are rather less squatly-shaped 
than the .species whicli we have just been describing, 
and they are more slender at the two extremities. The 
head is not so large as in many of the other viperine 
snakes, and is more elongated. It is flat on the crown 
and scaly, high on the sides, and shielded in front. 
The muzzle is rounded. The eyes are always shaded 
by' a plate over the eyebrows, and the pupil is oblong 
and erect. 
THE COMMOH VIPER or Adder ( Vipera or Pelias 
herns, represented Plate 4, fig. 3) is the most abundant 
and the widest-spread of the three species. It seldom 
exceeds two feet and a half in length, and in this 
country perhaps never reaches that extent. The cir- 
cumference of the body is generally that of a man’s 
thumb. The head is somewhat depressed, almost oval, 
slightly widening behind the eyes, and terminat d by' a 
somewhat conical muzzle bluntly rounded at the tip. 
In general it is of an olive or brown colour, with a series 
of confluent, rhomboidal, black spots along the back, 
and a row of small, irregular, triangular spots on each 
side. The colours, however, vary' considerably accord- 
ing to sex, age, climate, &c., and in the female the body 
is somewhat thicker than in the male, while the tail 
is shorter and more slender. This species is spread 
over the greater part of Northern and Central Europe, 
extending probably to some parts of Asiatic Kussia. 
It is common in Great Britain, and is happily the sole 
representative of the poisonous serpents in these isles. 
It is abundant in many parts of Scotland, England, and 
Wales, but has never been met with in Ireland. It 
frequents heaths, dry woods, and banks; preferring 
districts exposed to the rays of the sun, where there 
exists a plentiful supply of food, and which contain 
numerous holes which may serve it as places of retreat. 
Its food consists in great part of field-mice, and thus 
we find the Adder always most abundant in such places 
as these little mammalia are in the habit of frequenting, 
and it is such holes as they dig that these reptiles 
choose as their place of abode. Oti the continent ot 
Europe it appears to shun places covered with large 
trees, and forests where the rays of the stm do not 
penetrate, preferring on the contrary rocky' places, oi 
situations covered with small brushwood. Wherevei 
it is found it is universally dreaded. In this country 
its bite is seldom or never attended with fatal results ; 
but at the same time the symptoms produced by the 
venom are distressing in the extreme, and in warm 
countries, and during the height of summer, may even 
terminate in death. The manner in which the Viper 
inflicts a blow is thus described by Professor Bell : — 
“ The animal generally throws itself in the first plaC'"* 
into a coil more or less close, and the anterior part ot 
the body is raised. The neck is bent somewhat 
abruptly backwards, and the head fixed almost hori- 
zontally. In an instant the head is, as it were, 
launched by a sudden effort toward the object of its 
