So?, 



Length of the hody I'xpiesseil in millimetres 



Lenslh of the hcnd 



„ „ ,, .. rcdueed (from the hind extremity of the iutermnxillnri 



gia of the preopcrculum) 



Hravdth of the inlLToi-bitiil space 



Length of the snout 



% of the length of the boJ> 



to the hind mnr- 



id the tin of the snout.. 



„ ,. lower jnw 



Longitlldinnl diiimeler of the ey 



Vertieal 



Length of the suboperculnm 



Distance between the dorsal lin 



Base of the dorsal tin 



Height , 



Length of the pectoral tins...; 



Prcabdominal length 



Distance between the veutral tias and the tip of the snout 



Length of the ventral tins 



Postabdoniiual length 



Base of the anal fin 



Height.. ., ,. „ 



Dorsal margin of the peduncle of the tail 



Ventral ,, ., „ ,, 



Least depth of the tail 



Length of the middle caudal rays 



., ., ., longest ,, ,, 



Breadth of the maxillarics in % of the length of the head rcdi 



„ ., ., ., „ „ „ ,. ., „ mnxillarii 



Number of gill-rakers in the outer row on the first branchial 



Xumbe 



of scales 



longitudinal ro 



f the right side 



„ „ „ „ ,, „ left „ ._.. 



', ,, of the length of the body just above the lateral 1!) 



aud in front of the dorsal tin 

 ., .ibove the anal fin 



S.9 

 13.0 

 3.1 

 ;5.i 



5.4 



42.3 



11.8 

 IS.ii 

 15.1 

 29.0 

 49.2 



11.8 



■20.4 



8.5 

 12.2 

 11.3 

 12.1 



14.4 



14.S 



24.7 



15 



15 



20 



17 



The first two columns of this table show 1 ) the 

 differences between typical Trout and Salmon, 2) the 

 developmental alterations of Salmons during the more 

 advanced stages of growth, the latter partly I)ecause 

 the Trout, as we have proved above, in most of their 

 characters represent the earlier stages of growth, parti}- 

 because the specimens measured were on an average 

 shorter than the typical Salmon included in the table. 

 The last two columns, on the otiier hand, sliow the 

 relation of the Salmons to the Charr; and although the 

 Charr measured were tjn an average shorter than the 

 Salmons, still we see that in the great majority of 

 cases the percentages of the former Ijetoken a more 

 advanced development, in the direction indicated by 

 the changes of growth in the tirsr columns of the 

 table. Where the relation is the contrary, and cannot 



lie explained liy the difference of age, as in the case 

 of the distance between the dorsal fin and the tip of 

 the snout in proportion to the length of the bodj-, or 

 the breadth of the raaxillaries in proportion to tlieir 

 length, another factor, the difference of sex, has as- 

 serted itself. In the males the dorsal tin is, as a rule, 

 situated further back, and the maxillaries are longer, 

 than in the females; and here the Charr repre.sents the 

 male characters. 



The Salmon, like otiier fishes, is subject to va- 

 rious malformation.s. Tiiese are especially prevalent 

 and have received most attention at hatcheries", where 

 the fry live under more or less unnatural conditions, 

 and wliere there is bc^tter opportunity for observation 

 than in nature. One of these deformities, that may 

 often be seen, is the so-called pug-nose (reduction of 



" See, for example, Day, British and Irish ^almonidic, \>\. XII. 



