750 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



I have likewise found that the lower jaw of the older male individuals 

 of the winter-salmon never shows such a striking hook as the fruitful 

 male of the salmon (the hooked salmon). There is also a difference in the 

 color of the winter-salmon and spawn-salmon. The winter-salmon has a 

 grayish-blue back and silver-white sides, while the spawn-salmon has a 

 darker, frequently reddish-gray, color. The former has on the sides only 

 a few black spots, and the latter lias on the sides and the gill-covers num- % 

 erous red spots. The urogenital papilla is scarcely noticeable in the 

 winter-salmon, while it is large, protruding, and swollen on the edges in 

 the spawn-sal mou. The winter-salmon, on the other hand, generally 

 reaches a greater weight than the spawn-salmou, and its flesh is redder 

 and fatter. With regard to size and weight, therefore, the case seems here 

 to be just the opposite to what Siebold has found in Trutta lacustris. 1 



All these facts, therefore, seem to be in favor of the supposition that 

 the winter-salmon is the permanently barren variety of Trutta salar. 

 But, in spite of this, I have arrived at the conviction that this barren- 

 ness is only temporary, 2 and that those fish which one autumn and 

 winter appear as barren wiuter-salmon probably spawn as spawn-salmon 

 during the next spawning-period. 3 After I had continued my observa- 



1 The opposite from the winter-salmon seems ^o be the case in the barren Ti-utta 

 lacustris, also with regard to the quality of the ilesh. Siehold, at least, says that, in the 

 Lake of Constance, the thin and barren " Schwebforelle" is esteemed much less than 

 the fruitful " Grundforelle," (p. 309.) The barren Trutta fario, (common trout,) on the 

 other hand, has a better flesh than the fruitful one. 



i Giinther (op. cit., p. 8) says: Siebold "appears to have gone too far when he stated 

 that this state of sterility extends over the whole period of existence of such indi- 

 viduals." In " Nya Bidrag till Kiinnedommen om Sveriges Salmonider," communi- 

 cated in the " Kougl. Vetenskaps-Akademiens Forhaudliugar," Stockholm, 1865, Wide- 

 gren has shown in very young (one to three years' old) individuals of Trutta trutta 

 and Trutta salar that this barrenness, which occurs in nearly one-half of all these fish, 

 is only temporary. He mentions, as the chief difference between barren and fruitful 

 fish, that in the barren ones the shorter middle ray of the caudal fin is not as much as, 

 or, at most, not more than, half the length of the lougest outer ray, while in the fruitful 

 ones the shortest ray exceeds a little more than half the length of the longest one. 

 This, in itself somewhat subtle distinguishing mark, (he gives, e. g., the proportions of 

 19:40 mm. in the sterile against 20:38 mm. in the fertile, p. 290,) which is subject to ex- 

 ceptions (p. 280,) forms no criterion in the case of older individuals, as the caudal fin 

 more and more loses its emargination as the fish grow old. — (See Siebold, p. 295.) TYide- 

 grcn then goes on to show that in the barren fish the sexual organs develop gradually ; 

 that the proportion between the longest and shortest ray of the caudal fin gradually 

 becomes the same as in the fruitful ones ; that the color changes, &c. 



3 TYidegren thinks that several years may elapse before the barren ones become fruit- 

 ful (p. 202). William Broun, on the other hand, ("Natural History of the Salmon by 

 the Recent Experiments at Stormontfield," quoted from TYidegren, p. 294,) says (p. 48) 

 that of the young female fish which had been marked before going to the ocean, some 

 returned in the autumn of the same year for the purpose of spawning, while others 

 did not return till the autumn of the following year. Von dem Borne says (p. 339) : 

 " There are among the salmon some which spawn only every other year, just as there 

 are among the young salmon some which only leave the fresh water after two years. 

 (I must here remark that von dem Borne cites this fact from English sources, which 

 were not accessible to me.) I, therefore, think that the same applies to those salmon 

 whose home is the Rhine. 



