730 
SCANDINAVIAN FISHES. 
Pike-perch are also of service, though not in exactly 
the same degree. But large numbers of other fishes, 
especially of the Carp’s own family, such as Roach, 
Rudd, or Crucian Carp, only do mischief. The most 
practical method of keeping the ponds clean, a method 
which at the same time renders their bottom better ca- 
pable of developing food for the Carp, is to drain them 
in turn and leave them dry for a year, during which 
period they may be ploughed and sown, in most cases 
with good results. They must also be emptied to faci- 
litate the transfer of the hsh from one pond to the 
other, an operation which should be performed during 
the cool season, in autumn or spring, the heat of sum- 
mer being at best disagreeable to the Carp on dry land. 
It is obvious that the ponds should also be protected 
from the inroads of poachers, otters, herons, and other 
enemies of the Carp; but ducks do no damage. The 
reader who desires fuller information on this head, will 
find what he needs either in Norback’s Handledning i 
Fiskevard och Fiskafvel (p. 257) or in the numerous 
German manuals on the subject, e. g. Max v. d. Borne, 
Handbuch der Fischzucht und Fischerei , Berlin 1886, 
p. 261. 
Among Carp as among other domesticated fishes 
we frequently meet with deformed individuals. One of 
these examples, not uncommon in its occurrence, with 
the snout apparently reduced, is described by Valen- 
ciennes' 1 . The reduction, however, does not really affect 
the snout or the jaws, which parts are developed as 
usual, or only distorted, the frontal bones, on the other 
hand, being anteriorly depressed, and the basisphenoid 
and parasphenoid bones reduced. 
In the pond the Carp is a victim to all kinds of 
diseases. We sometimes hear of Carp being so old that 
moss has begun to grow on their bodies, this moss 
As we have mentioned above, many cultivators 
of the Carp are unfortunate enough to have their 
breed of fish spoilt by crossing with the Crucian Carp. 
being really a mould fungus, Saprolegnia, of the same 
genus as the scourge of the Salmonoids. The best re- 
medy for this is a little salt in the pond or a change 
of water. By unsuitable food the whole stock of a pond 
may be poisoned. Carp may be fed and fattened on 
ordinary kitchen-refuse, brewer’s grains, boiled and 
mashed potatoes, chopped cabbage, guano, or the dung 
of the horse, pig, or sheep. But experience, according 
to M. v. d. Borne and others, shows the necessity of 
great caution, and the economical results of fattening 
have not been satisfactory. Carp are often troubled by 
the male frogs, which under the influence of sexual 
excitement attach themselves firmly to the head of the 
sluggish Carp, and with their forefeet press the eyes 
of the fish so hard as to produce blindness. 
For all this the Carp is an easily fed and easily 
managed domestic animal; but without expensive pre- 
paration for table its culinary value is even less than 
that of the Pike. In the south of Europe its roe is 
made into caviare, consumed principally by the Jews, 
who are forbidden by law to eat genuine caviare, the 
Sturgeon being destitute of ordinary scales. 
The age attained by the Carp is not yet ascer- 
tained. Buffon mentioned Carp 150 years old as exist- 
ing in the moats at Pontchartrain, and Lebel stated 
that the ponds at Lausitz * 6 contained Carp 200 years 
of age. It is difficult, however, to test the truth of 
these old statements, and the same difficulty applies to 
Bloch’s account 0 of the capture in 1711, at Bischof- 
hausen near Frankfurt-on-the-Oder, of a Carp 6 feet 
long, 2V 5 feet deep, with scales as large as an 8- 
groschen piece, and 70 lbs. in weight. In a state 
of freedom, according to Heckel and Knee (1. c., p. 
57), the Carp only attains the age of about 12 or 15 
years. 
The hybrid produced by this cross-breeding has gene- 
rally been known among modern ichthyologists by the 
name of 
a Cuv., Val., Hist. Nat. Poiss., vol. XVI, p. 57. 
6 See Lacepede, Hist. Nat. Poiss., tome V, p. 510 and Bloch, Naturg. Deutschl. Fish., part. I, p. 
c Cited from Beckmanns Gesch. der Chur., Th. I, p. 574. 
95. 
