THE GERMAN CARP IN THE UNITED STATES. 569 
the spring the Silesian carp, though apparently well nourished, had 
reached a length of only 5 to6cm., while the Galician carp had grown 
to a length of 18 cm. The author answers the question, Wherein, 
under natural conditions, rests the ability for quick growth in fresh 
water fishes? by saying: ‘‘ Partly, perhaps, ina better assimilation of 
the food, but mostly upon a better selection of the same. The richer 
this is in nitrogen, the greater, within certain limits, is its nutritive 
effect.” (Zoologische Garten, Jahrgang 37, 1896, p. 345, 346.) 
In order to determine the nature of the principal food of the carp 
in this country I have examined the alimentary tracts of a great many 
individuals. Many of these examinations were not made in detail, 
but only to determine the presence or absence of certain things, such 
as the eggs of other fishes. A list of the contents of stomachs and 
intestines of 33 carp, however, is given below. These examinations 
were made with more care than the rest, but are for the most part 
only qualitative, the relative quantities of the various materials being 
given only in rough approximates. The carp were from several dif- 
ferent localities and a variety of conditions. The list is given in full 
because it is believed to be important to convey a very thorough knowl- 
edge of the nature of the food of the carp in our waters. I have never 
found large particles of food of any kind in the alimentary tract, the 
largest being strips of vegetable epidermis perhaps an inch long, 
wings and other portions of insects, small snail shells, and the like. 
It is stated that carp can grind or ‘‘ masticate” thin food to a certain 
extent with the flat, knob-like pharyngeal teeth, and probably this in 
part explains the fact that what is found in the stomach is usually so 
much broken up. Houghton (1879, p. 17) even maintains that ‘* por- 
tions of vegetable food are returned to the throat and remasticated by 
these pharyngeal grinders,” though I know of no evidence in support 
ef this hypothesis. The finely ground condition of the stomach con- 
tents leads to some wonderment among the fishermen, who are accus- 
tomed in other fish to find the food, such as smaller fish, swallowed 
whole, and one man always insisted to me that carp ‘‘ digest their food 
in their heads.” 
1. Specimen from St. Clair Flats, June 30, 1901. Chara, small 
anount; May fly (ephemerid) wings and broken fragments, consid- 
erable numbers; insect larvee, small; roots, decaying leaves, and epi- 
dermis (‘‘bark”) of aquatic plants, large amount; small shells and 
fragments; sand. All the Chara seemed to be packed in the small 
intestine. This was noticed in other cases, and seems to indicate that 
when the fish get among the Chara they eat a large amount of it. 
2. Specimen from St. Clair Flats, July 3,1901. Rootlets and other 
vegetable matter, such as would be found in bottom mud; coleopter- 
a¥For a more detailed discussion of the processes of digestion and assimilation in the carp, the 
reader is referred to a later paper by Knauthe (1898). 
