lO ESDAILE, Scales of three Specimens of Salvio salar. 



annuli per period than those from a corresponding position 

 on the dorsal side. (See Graphs i and 2). 



As it was thought desirable to obtain data from 

 another fish, Mr. Hutton obtained more scales — in this 

 ca.se from a 261b. fish caught at Hampton Bishop, 

 loth March, 191 1. It was a male, freshly run, measuring 

 41%" in length and 20^" in girth. The results from this 

 fish do not appear to be as regular as those obtained 

 from the 171b. fish ; but on the whole it can be said that 

 the same general arrangement is followed in spite of the 

 many irregularities. The records of the scales from the 

 261b. fish are to be found in Table 3 and Graphs 3 and 4. 



Endeavours have been made to ascertain whether 

 this increase and decrease in the number of annuli per 

 l^eriod can be expressed as a definite ratio and follow some 

 rule. One might have imagined that some mathematical 

 formula could have been found to express the variations, 

 but, so far, I can find no connection between the results, 

 and no formula which will help to make clearer what 

 now appears to be a chaos of figures. For this purpose 

 the averages of the three series of records, on the long 

 axis and at 30*^ to the left and right, were obtained (see 

 Table 4 A). From this Table it is quite easy to ascertain 

 the rate of increase and decrease in the number of annuli 

 which is shown in Table 4 B. On examining these 

 figures it will be seen that there seems to be no definite 

 rate of increase and decrease either on the dorsal or 

 ventral side. There is no constant variation in the 

 number of annuli in the different periods of scales from 

 the same position ; there is no definite variation in the 

 number of annuli in the periods of scales from different 

 positions. And comparing the results of the two fish 

 there seems to be no law or theory which could be 

 applied to both. 



