53 



oxamiucd iLc uuiubors Lave ran<,'od from 11 to It, but in no 

 instance in fisli taken below Bridgewater has the number 

 exceeded 14. 



In the detailed descriptions of various specimens of salmo 

 saJar in the British Museum the number of these scales is 

 \infortunately omitted, but in four instances the number in the 

 transverse series desccndini? obli(]i;ely backwards from tho 

 origin of the dorsal fin to the lateral line is given as well as 

 the number of the longitudinal scries of scales between tho 

 lateral line and the base of the ventral. In one adult the 

 iu;mbcrs arc I ^ ; in another adult || ; in the third in the 

 grilse stage -j .} ; and in the fourth a parr |5-. 



Next let us turn to Dr. Giiuthcr's descriptions of the salmon 

 trout in the Museum, and wo find that the number of 

 scales between the adipose fin and the lateral lino vnries 

 even in the adult fish from 13 to 15, the latter number never 

 having yet been found in any of our salmonoids taken in 

 salt water. 



The male siliolt from England already mentioned contains 

 only one scale less in this series (viz., 13) than the second 

 grilse, Avhile tho salmon parr preserved in our Museum, 

 which was hatched from an English ovum, has 14 on one 

 side and 13 on the other. 



Now, finding this discrepancy coupled with the great 

 variation in the nximbers exhibited by our own salmonoids, 

 arc we not justified in concluding that, however constant 

 Avithin certain limits, this test may be in mature fish, that 

 as applied to immature specimens, it is all but valueless ? 



Dr. Giinther's next reason — " numerous x shaped spots on 

 the body " — requires very few words. When fresh from the 

 water the second grilse was perfectly free from spots bf low 

 the lateral line, and had but few above that line ; shortly 

 after the immersion in spirit, however, several more spots be- 

 came apparent, and the same thing took place with the first 

 grilse. On turning to Dr. Giinther's descriptions, I find details 

 of only one specimen of true salmon, which approximates in 

 size to the second grilse. This is a male, 22 inches long, in 

 reference to which Dr. Giinther writes : — " Upper i)arts 

 greenish, which colour gradually passes into the silvery hue 

 of the belly. There are some scattered x shaped black spots 

 on the side of the back above the lateral line." 



It is curious that the above description occurs only in the 

 solitary instance in which the size and sex agrees with the 

 second grilse, because no test is so variable as the fleeting 

 one of colour, which in the salmonidic (as in most fish) is 

 Iierpelually liable to change raj.idly fiom causes as yet 

 unexplained. 



