204 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
tial to stagnant waters or such as have not a too swift current, with 
a loamy, muddy bottom and deep places covered with vegetation ” ; 
further, “it is an advantage that the carp is able to live in water 
where other fishes could not possibly exist; for instance in the 
pools of bog-meadows or sloughs.” Nevertheless, “it is not by any 
means to be inferred from this that the best locality for carp ponds 
of a superior kind” should be “in such situations. The presence 
of too much humic acid is unfavorable to the well-being of the 
carp.” In short, its preference generally appears to be for “ places 
with a luxuriant vegetation, being by no means averse to a muddy 
bottom, but requiring clear water and free access to the sunlight.” 
But it is not even confined to the fresh water ; it is, to some extent, 
tolerant of salt; in the words of Smitt, it can “ endure salt water.” 
In the Caspian sea even, if Pallas is to be credited, “the carp lives 
in water so salt that hardly any other fish can sustain life there.” 
Its occurrence in brackish waters in many places has been recorded. 
Although individuals endure for a time wide differences of tem- 
perature, they flourish best in water which is not overheated or too 
cold. Tropical countries and those where cold prevails for nearly 
half of the year, as in Scandinavia or the northern part of the Cana- 
dian Dominion, are not favorable to their continuous development. 
They are indeed “ highly sensitive to heat and cold.” 
They manifest the effect of cold by seeking warmer resorts and by 
abstention from food. “In the moderate zone” (e. g., Central 
Europe or the middle United States), “the carp will, at the begin- 
ning of the cold season, seek deeper water to pass that period in 
a kind of sleep. This will sometimes occur as early as the begin- 
ning of November if the winter should set in early; and it is to be 
remarked that they will retire at an earlier period in ponds than 
in rivers. They do so always in groups of from fifty to one hundred 
and more. They make a cavity in the muddy ground, called a 
‘kettle’; in this they pass the time until spring, huddled together 
in concentric circles with their heads together, the posterior part 
of the body raised and held immovably, scarcely lifting the gills 
for the purpose of breathing, and without taking a particle of food. 
They do not take any food from the beginning of October and con- 
tinue to abstain from it, in some countries, until the end of March, 
and in colder districts even somewhat later.” 
Tenacity of life is another attribute of the carp. It is claimed 
that in this respect the carp surpasses all its compatriots except the 
eel. This characteristic enhances its commercial value as a market 
fish, for it can be carried for long distances and displayed on the 
