THE GERMAN CARP IN THE UNITED STATES. 581 



darker in its posterior half; the ra3^s themselves are of about the same 

 color. The anal is yellowish-red, while the pectoral and pclv'ic fins 

 are grayish or ^^ellowish, tending to red toward their tips. The upper 

 lobe of the caudal fin is of about the same color as the dorsal; the 

 lower lobe has a lighter, yellowish cast, with more or less red, especially 

 toward the end. 



The coloration is influenced by the age of the fish, the character of 

 the water in which it lives, its nutrition, the season of the year, its 

 sexual condition, and b}^ the other conditions of its environment. 

 Seeley (1886, p. 97) states that unsymmetrical coloring is sometimes 

 found and that a fish may have glittering golden stripes on one side of 

 the body and pale steel blue on the other. Sometimes t^^pical carp are 

 black, bluish, green, red, golden, silvery, or even white, and Doctor 

 Fatio records that he has kept in confinement carp which Avere origi- 

 nally green or golden, but which became colorless in an opaque vase. 

 It is not an unusual thing to see in carp that have died out of water 

 a reddish suffusion, especiallj^ marked in the fins, probably due to the 

 congestion of blood in the capillaries as the circulation is stopped. 



In common with the other members of the family, the mouth of the 

 carp is without teeth, the only organs of this description being the 

 blunt, knob-like sti'uctures lying on the pharyngeal bones in the back 

 part of the mouth, or "throat." These are entirely for grinding 

 food, and, as is obvious both from their position and shape, are of no 

 use in grasping, this function being performed by the so called lips. 

 The alimentary tract is comparative!}^ long, but uncomplicated; the 

 stomach is a simple tube not sharply differentiated from the esophagus 

 and without a blind sac, while the intestine has no p vloric appendages. 

 The entire alimentary tract from the beginning of the stomach '^^ is 

 usually two to two and one-half times as long as the body. The air 

 bladder is large, with tough, thick walls. A transverse constriction 

 divides it into two parts; the posterior of these is the smaller and 

 ends in a rounded point, while the anterior portion is larger and has 

 its base somewhat bilobed. 



RACES AND VAEIETIES. 



The great range and frequency of variation in the carp is undoubt- 

 edly largely due to its domestication or semidomestication since early 

 times. As is to be expected, this has resulted in the naming of a large 

 number of varieties or races. In Europe, where carp culture is car- 

 ried on systematically, these races are kept pure and true, so far as 

 possible; but in this country no attention has been paid to them, at 

 least in recent years, so tfiat we need not treat them in detail liei-e. 

 Those interested in the subject will find an exhaustiv^e account in the 

 contribution entitled "tjber Kai-pfenrassen," by Dr. Emil Walter, in 



a The position of tlie thoracic septum is here taken as the beginning of the stomach. 



