45 8 
TUBE-BLADDERED GROUP. 
quently into Britain—it is said early in the seventeenth century. The ordinary 
form is shown in the upper figure of the illustration on p. 457 ; hut there are many 
domesticated varieties, differing either in the form of the body or the size and 
arrangement of the scales. Among the latter, one of the most remarkable is the 
so-called spiegel-karpfen (mirror-carp), shown in the right-hand middle figure of 
the illustration. In this variety, which is found only in ponds, the scales are three 
or four times the normal size, and instead of covering the whole body are arranged 
in from one to three longitudinal rows, with bare skin between them. In Western 
Europe the carp has taken kindly to its new habitat, not unfrequently attaining as 
much as a yard in length, with a weight of 25 lbs., while very much larger specimens 
are on record. Preferring still waters, with a soft muddy bottom in which it 
grovels with its snout for food, the carp feeds on various vegetable substances, as 
well as on insects and other small aquatic invertebrates. When the surface of their 
haunts is locked in ice, carp lie deeply buried in holes in the mud, frequently 
consorting in numbers, and undergoing a partial hibernation, which is not broken 
till the returning warmth of spring. Their growth is extremely rapid, and their 
fecundity extraordinary, nearly three-quarters of a million eggs having been counted 
in the roe of a medium-sized specimen. They are capable of living a considerable 
time out of water, especially if they are moistened from time to time; and are 
known to live to a very great age. Carp will interbreed both with the Crucian 
and golden carp. 
Crucian and Easily distinguished by the absence of barbels, the Crucian carp 
Golden Carp. (Carassius vulgaris), and the golden carp, or gold-fish (C. auratus} 
are the best known representatives of another closely allied genus; the former 
being a native of Central and Northern Europe, but also found in Italy and Siberia,, 
while the home of the second is China and the warmer parts of Japan. Both are 
comparatively small species, and have been long domesticated; whereas, howmver,. 
the Crucian carp always retain the original brownish colour, the domesticated 
variety of the golden carp has assumed the well-known golden tinge from which 
it takes its name; an albino form being also known. Among the numerous varieties 
of this fish the most curious is the so-called telescope-fish, shown in the right-hand 
figure of the illustration on p. 412, taking its name from the prominence of the 
highly movable eyes, and likewise characterised by the great development of the 
caudal fin. In Europe gold-fish thrive best in waters heated somewhat above the 
ordinary temperature, and they are accordingly frequently kept in engine-ponds, 
where the water may have a temperature of some 80°, and in which they breed 
freely. The Crucian carp, shown on the left of the illustration on p. 457, is con¬ 
fined to ponds and lakes, where it seeks the deepest parts. 
Barbels Represented by some two hundred species from the tropical and 
temperate regions of the Old World, the barbels are best known by 
the common European species (Barbus vulgaris), shown in the lower figure of the 
illustration on p. 457, and the gigantic mahasir (B. tor ) of India and Ceylon. 
Agreeing with the carps in the structure of the anal fin, and the position of the 
lateral line and dorsal fin, they belong to a subgroup of genera in which there are 
generally not more than nine rays in the dorsal fin, the pharyngeal teeth being 
arranged in three rows, the greater part of the cheek not covered with bone, the 
