740 
SCANDINAVIAN FISHES. 
the Crucian Carp gradually degenerates, and after some 
generations assumes the form described above under the 
name of the Pond Crucian Carp. This form never oc- 
curs in lakes or such localities as were first mentioned 
as the favourite haunts of the species. There only the 
Lake Crucian Carp is met with; but if specimens of this 
variety be put in a small fish-pond, in the course of 
some years the pond will be found to contain Crucian 
Carp of an intermediate form, difficult to refer to either 
variety, and at a still later period only Pond Crucian Carp. 
These two forms are consequently not distinct spe- 
cies, as was long assumed on Bloch’s authority. It is 
probable, however, that the Crucian Carp does not de- 
generate with equal rapidity everywhere, but that the 
course of degeneration is arrested at an earlier or later 
stage, according to the nature of the water and the 
supply of food. Small pools are, at all events, often 
inhabited by the said intermediate forms, which seem 
to have lived and multiplied there for a long time 
without further transformation. 
That the Pond Crucian Carp resumes its original 
form, is shown by the fact that if a few small speci- 
mens of this variety lie placed in a- large pond, where 
the supply of food is abundant, they soon acquire the 
intermediate form. But when they have been allowed 
to multiply to any great extent, so that food is scarce, 
and the pond overstocked, they revert to the normal 
form of the Pond Crucian Carp. Furthermore, we have 
actual evidence to show that specimens of the Pond 
Crucian Carp, which have been transferred to lakes, 
have at length been restored to the original form of 
the Lake variety. In a small lake in Sodermanland 
Eksteom found large Lake Crucian Carp, the progeny 
of Pond Crucian Carp which, according to the state- 
ments of trustworthy persons still living at the time, 
had been taken 40 or 50 years previously from a neigh- 
bouring pond still inhabited by the latter variety. 
Eksteom elucidated this question in the Proceedings 
of the Swedish Academy of Science for the year 1838; 
and at the present time his opinion on the subject is 
almost universally accepted. 
The Crucian Carp is very sluggish in temperament, 
never undertaking any long excursions, and always 
staying near its birthplace, unless compelled by fortui- 
tous circumstances to change its abode. This innate 
distaste for active motion deprives it of any great ti- 
midity and renders it oblivious of danger, as it hides 
in the ooze at the bottom, where the water is deep, or 
among the weeds nearer the shore. When it ascends 
towards the surface, which seldom happens except when 
the heat of the sun entices it forth, it is however shy, 
and takes to flight at any noise. It then makes straight 
for the bottom, and there seeks a safe refuge, from 
which it is not easy to unearth. Its movements in the 
water are often active and speedy, though they lack 
endurance. 
The spawning-season occurs in spring and summer, 
some days earlier or later according to the situation of 
the water where the fish has its home. In Central 
Sweden the Crucian Carp spawns in June, about mid- 
summer, when the weather is warm and tine. The fish 
then ascend to shallow water near shore. Here they 
spawn among the weeds, assembling in dense shoals 
and circling rapidly round each other, now and then 
raising their snouts above the surface, where each fish 
leaves a bubble that bursts with a faint sound. A 
murmuring hubbub, like the noise of boiling water, is 
thus produced. The roe is deposited at the bottom on 
the weeds, to which it adheres, and is soon hatched 
when the weather is favourable. The fry do not grow 
very rapidly, but soon reach maturity. This faculty 
of early reproduction, combined with the comparatively 
large size of the ovaries and the smallness of the eggs, 
their diameter, when deposited, being only slightly more 
than 1 mm., as well as their great number (100,000 
— 300,000 in each female), renders the Crucian Carp 
extremely prolific. The duration of the spawning- 
season is protracted, in this species as in others, by 
the older fish spawning first, the younger ones later in 
the year. But the erroneous supposition that the Cru- 
cian Carp spawns several times a year, has arisen from 
the circumstance that during the months of July and 
August, when the weather is calm and fine, these fishes 
shoal in exactly the same manner as when they are 
spawning. 
The Crucian Carp is a glutton, and lives on insects, 
worms, water-plants, and mud. The flesh ranks as a 
delicacy, but its reputation depends principally on the 
skill of the cook. Large Crucian Carp, taken in clear 
water, are best and by no means bad eating; but small 
specimens from muddy lakes always have a more or less 
tainted flavour, and their flesh is also bony. 
The Crucian Carp is extremely tenacious of life. 
In lakes and ponds where the bottom freezes, it can 
survive the winter, and after being kept frozen for a 
long time, may be restored to life by cautiously thawing 
