78 THE AGE AND GBOWTH OF SALMON AND TKOUT. 



them into the lake, and I have caught some of them and examined their 

 scales. The results are quite remarkable. One of their scales is to be 

 seen in Fig. 33 (Plate X.), which represents the scale of a trout 36 cm. 

 long that weighed 650 grammes. The trout has first grown very poorly 

 for three years, and has then spent a summer in Laugen, where it has 

 developed enormously. After the usual winter stagnation, the fish has 

 passed through another summer with again enormous growth. 



Similar illustrations of growth were afforded by all the 21 fish from 

 this lake that I examined, and the following table shows the averages 

 I got by my investigations : 



This is a clear instance of what beneficial and valuable use has been 

 made of these small slow-growing and relatively worthless fish, and it 

 shows how well they have been made to grow by transferring them to 

 Laugen. 



It is also interesting to look at the weights they attained in their first 

 and second summer, compared with the age and weight they had at the 

 time of transference. 



Average Weight of Fish which when Transferred had Completed 



This second table shows us quite clearly that it is apparently an 

 advantage to turn out older fish, and it might be well worth while 

 experimenting with the various possibilities suggested by these results. 



I have given these instances because they seem to me to indicate some 

 of the lines along which experiment and study of growth should go. 



* Found by calculating the average lengths of the fish at time of transference (from 

 measurements of the scales), and translating these lengths into average weights as per 

 Table XXXYin. 



