SALMO ISALAR. 269 



The colour o£ the back varies from a dark steel-bkie to bluish-black, 

 becomiug" paler on the sides in the adult, while the under side of the body is 

 silvery, with a mother-of-pearl lustre. The upper part of the head is bluer 

 than the back. The cheeks are silvery ; large black spots are scattered over 

 the frontal region above the eye and the operculum, and there are smaller 

 black spots which may be round, X-shaped, or star-shaped, on the back and 

 sides. Yarrell states there are usually more spots on the female than on the 

 male. About four or live may be counted about the lateral line in the fore 

 part of the body. Benecke mentions that in North Germany the head of the 

 male Salmon is sometimes spotted with red. At spawning'-time, and in old 

 males, these red spots become confluent in wavy lines, and the entire abdomen 

 is red. 



The dorsal fin is grey, with a dark border, and often has a row of small 

 black points at its base. The pectoral and caudal fins are similar in colour, but 

 in British fishes the fins are usually darker than on the Continent. The ventral 

 fins are white, but dusky on the inner side, while in Germany they are com- 

 monly pale red at the base. The anal fin is white. 



In the young stage, termed Parr, the sides of the body are marked with 

 about ten or eleven dusky cross bars which are vertically ovate in form. 

 There are some orange spots. The black spots on the l)ody are then few, and 

 almost entirely above the lateral line. 



A little later the fish is termed a Smolt, when the dusky patches become 

 fainter and the black spots more numerous ; and when the dark patches 

 are vanishing and become more elongated vertically, the Grilse stage is 

 reached, and then the pectoral fin loses its pointed character, and the scales 

 of the lateral line become paler. Under normal circumstances the Smolt 

 is on its way to the sea, and the Grilse on its first journey back from the sea 

 to the spawning-ground. In the sea the colours are bright, and the silver 

 scales exceptionally shining, but on entering fresh water all the tints become 

 duller ; and fish have occasionally been captured which have become brown or 

 coppery. 



Not much is known of the food of the Salmon while they are in the sea, 

 but they feed greedily on sand-eels. Smelts, sea-urchins, starfishes, shrimps 

 and other Crustacea, and the fry of all kinds of sea fishes. Very little food, if 

 any, is found in the intestines of Salmon caught in rivers, yet from their 

 taking bait, such as lug- worms, they certainly feed, and it is quite possible that 

 the increase of weight of the fish bears no proportion to the weight of solid food 

 taken. After spawning they develop cannibal propensities, and the old feeble 

 Kelts or Kippers, which remain in the rivers grow voracious, and consume im- 

 mense quantities of Salmon fry, before they recover streng-th enough to go down 



