532 REPOKT OF THE COMMISSIONER OF FISHERIES. 



* 



the recent book by Knauthe (1001). These names have often been 

 given speciiic value and were bestowed usually cither for characters 

 of the integument or of form (cf. (jtinther, 1868, p. 26); thus we have 

 such names as Cyprinus macrolepidotas^ O. rex cyjjrlnorimi^ C. specu- 

 lar is (for the mirror carp), 61 nudiis (leather carp), and C. cirrosus^ 

 C. regina, C. hungaricus^ (J. elatus^ C. acumlnatus^ etc., and C hyhis- 

 coides^ a variet}' with the fins much prolonged. This list of synonyms 

 might be extended much further. 



Hessel (1881) considers all the varieties of carp as falling into three 

 chief groups, which he distinguishes as follows (op. cit., p. 867) :** 



1. Cypriniis carpio communis, the scale carp; with regular, concentrically-arranged 

 scales, being, in fact, the original species improved. 



2. Cyprinus carpio specularis, the mirror carp; thus named on account of the extra- 

 ordinarily large scales, which run along the sides of the body in three or four rows, 

 the rest of the body being bare. 



3. Cyprinus carpio corviceus, or nudiis, the leather carp; which has on the back 

 either only a few scales or none at all, and possesses a thick, soft skin, which feels 

 velvety to the touch. 



Walter (Knauthe, 1901), however, says the scale, mirror, and leather 

 carp must not be considered as distinct species or races, although the 

 conditions of the scales are characteristic, since a similar differentiation 

 of the scales, or at least a tendency to it, is found in every true race 

 of carp. In many ponds where one of these forms (i. e., scale, mirror, 

 or leather) has been raised, the others have appeared spontaneousl3^ 

 He concludes that they should be considered only as varieties. He goes 

 on to say that the ordinary characters are so inconstant and variable 

 that sharp lines can not be dravrn between the various intergrading 

 races. In his opinion, the division into races should depend princi- 

 pally upon the relations in size of various parts or measurements of 

 the body, though he correlates with this set of characters three others, 

 viz, (1) rate of growth (i. e., the ability for rapid growth); (2) adapt- 

 abilit}' to climatic changes, and (3) time of sexual maturity. He then 

 develops a rather artificial classification, depending mostl}^ as he savs, 

 upon the two ways in which the flesh is disposed upon the back; that 

 is, whether there is a large development of the dorsal musculature, 

 forming a highly arched outline, often v/ith a hump and a reentrant 

 angle back of the head, or whether the dorsal outliric is low and com- 

 paratively straight. He uses as a measure of this the ratio of the 

 height of the body to the length. This ratio is designated by the 

 letter V in the following classification, translated from his paper (p. 86): 



I. Cultivated races; y = l:2to]:3. 



(a) High-backed cultivated races; V=l:_2 to 1:2.6. 

 {h) Broad-backed cultivated races; V=l: 2.61 to 1:3. 

 II. Primitive and degenerate races; V=l:3.01 to 1:3.6. 



Here belong also those forms under the size ratio 1: 2 to 1: 3 which do not 

 have a breadth in correspondence with their size ratio. 



a The blue carp, so called, is probably but a color phase, and not a true "variety." 



