34 THK ROYAL SOCIETY OF CANADA 



lines, which iiKlicato successive iiicicineiits of growth, they present 

 also a number of radiating grooves, that divide the various concentric 

 lines into segments and complicate somewhat the study of the scales. 

 And this complication is increased by the fact that the scales are small 

 and the number of annual periods represented great as compared 

 with the scales of a Salmon, for instance, and because, especially in 

 older fish, the scales are so thick as to obscure the distinctness of the 

 markings. 



In a fish measuring 66.5 cm. from the tip of the snout to the root 

 of the tail, each scale (Fig. 1) showed clearly a nucleus, situated very 

 excentrically near one extremity, and immediately succeeding it were 

 a number of lines (I) very close together, which may be taken to repre- 

 sent a winter's growth. These were succeeded by a zone in which the 

 lines w^ere appreciably farther apart and which may be assumed to repre- 

 sent a summer's growth and accordingly this, together with the initial 

 zone of narrow lines, represents the growth of the fish during the first 

 year of its life. This annual area is succeeded by a second narrow band 

 of fine lines (2) and this b}^ a second zone of broader ones, the two to- 

 gether again representing the growth of the second year. So, passing 

 along the longest axis of the scale, one finds zones of narrow and broad 

 lines alternating with one another, the scale ending with a zone of 

 broad lines indicating the growth of the summer in wdiich the fish was 

 caught. Starting with the narrow lined zone immediately succeeding 

 the nucleus, it was found that in all seven such zones could be distin- 

 guished upon the scale, and, assuming that each of these represents a 

 winter's growth, we reach the conclusion that the fish was in the seventh 

 year of its age when caught. 



Throughout the entire scale no indication of any marked inter- 

 ruption of growth, such as might be produced by spawning, was to be 

 seen, and the evidence of the markings is to the effect that the fish 

 required seven years to reach a length of 66.5 cm. and that up to that 

 time it had not spawned, in other words, that it required at least seven 

 years to reach maturity. 



The next fish from which uninjured scales were obtained measured 

 122 cm. in length. The markings upon its scales (Fig. 2) were essenti- 

 ally the same as those on the 66.5 cm. fish up to the seventh summer 

 zone, except that the fifth winter band (5) was much broader and the 

 lines comprising it greatly broken and indistinct. Beyond the seventh 

 summer zone are the markings representing the additional growth, the 

 additional age of the larger fish. These show first a narrow band of 

 fine lines (8) representing the eighth winter and then follows a broad 

 zone in which the lines are broken, somewhat indistinct and closer 

 together than are the summer lines in the older portions of the scale. 



