For each of the experiments, the following methods have been adopted, in order 

 to determine the general mean direetion of tlie migration, and the distance 

 travelled : — 



I. The exact direction of the migration of each fish being ascertained from the 

 nearest compass on the chart, and the distance it had travelled, the sum of the 

 figures for direction and for distance was divided by the number of fish whose lines 

 of migration fell within that quadrant of the circle. Thus, in Experiment II., eight 

 adult females migrated north and east in directions from N. 24° E. to N. 58° E., 

 and for distances which ranged from 5 to 68 miles, the aggregate being 328"5 miles, 

 or an average of 41" 1 miles, and the mean direction, as ascertained in this way, was 

 N. 33° E., or parallel to the coast. Four adult females migrated north and west, 

 in directions varying from N. 62° W. to N. 84° W., for distances of from 21 to 

 23 miles, the aggregate being 89 miles, and the average 22 miles, while the mean 

 direction was N. 77° W. 



The other quadrants were treated in the same way for each sex, and the results 

 for this experiment were as follows : — Thirteen plaice moved north and east, in the 

 mean direction N. 32° E., for an aggregate distance of 634*5 miles, the mean being 

 48'8 miles ; 10 migrated north and west, in the direction N. 71° W., the aggregate 

 distance being 220 miles, and the average 22 miles ; 9 moved to the south and 

 west, in the mean d-rect'on S. 55° W., the aggregate distance being 97'5 miles, 

 and the mean distance travelled 10*8 miles. 



Each of the experiments made at this station has been treated in this way, 

 and the results are shown in the accompanying table. 



N. and E. 



N. and W. 



Experi- 

 ment. 



I. 



II. 

 III. 

 IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X. 



Date. 



28 Nov. 1910 

 21 Mar. 1911 



25 Apr. 1911 

 19 June 1911 

 11 Sept. 1911 



7 Mar. 1912 

 24 Apr. 1912 

 10 May 1912 



6 Dec. 1912 



26 Mar. 1913 



Average 





Miles. 

 3,523 



634-5 



764 



620 

 1,518 

 1,018 

 1,241 



470-5 

 4,169 

 1,498 



268 15,456 

 ... 1545-6 



>- CO 



Miles. 

 76-6 



48-8 



85- 



48- 



58-4 



50-9 



45-9 



33-6 



58-7 



51-7 



557-6 

 55-8 





27° E. 

 32° E. 

 37° E. 

 40° E. 

 33° E. 

 33° E. 

 39° E. 

 45° E. 

 31° E. 

 29° E. 



346- 

 N. 34° E. 



S. and E. 



I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X. 



S. 31° E. 



27° E. 

 26° E. 

 26° E. 

 65° E. 

 31° E. 

 28° E. 

 17° E. 

 48° E. 



299° 

 S. 33° E. 



Experi- 

 ment. 



I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X. 



Date. 



28 Nov. 

 21 Mar. 



25 Apr. 

 19 June 

 11 Sept. 



7 Mar. 

 24 Apr. 

 10 May 



6 Dec. 



26 Mar. 



1910 

 1911 

 1911 

 1911 

 1911 

 1912 

 1912 

 1912 

 1912 

 191 



Average 



114 





Miles. 



57 

 220 



91 



33 

 132 

 350 



93-5 

 171-5 

 526-5 

 227-5 



1,902 

 190-2 



^S 



Miles. 

 11-4 

 22- 

 18- 

 16-5 

 16-5 

 16- 

 11-7 

 13-2 

 18-8 

 17-5 



161-6 

 16-2 



N. 45° W. 

 N. 71° W. 

 N. 46° W. 

 N. 42° W, 

 N. 62° W. 

 N. 52° W. 

 N. 39° W, 

 N. 41° W, 

 N. 57° W, 

 N. 61° W, 



516° 

 N. 52° W. 



S. and W. 



1. 



JI. 

 III. 

 IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X. 



28 Nov. 1910 

 21 Mar. 1911 

 25 Apr. 1911 

 19 June 1911 

 11 Sept. 1911 



7 Mar. 1912 

 24 Apr. 1912 

 10 May 1912 



6 Dec. 1912 

 •26 Mar. 1913 



Average 



149 



S. 58° W. 

 S. 55° W. 

 S. 55° W. 

 S 53° W. 

 S. 53° W. 

 S. 50° W. 

 S. 53° W. 

 S. .58° W. 

 S. 61° W. 



S. 37° W. 



.^.33° 

 S. 53° W. 



Note ; In Experiment V., 2 fish went directly N., each for 2 miles. 



In Experiment VII., 2 went directly W. for a mean distance of 10 miles ; 2 went dii'ectly E. 



for a mean distance of 22 '5 miles. 

 In Experiment IX., 3 went an average of 9 miles directly W., and 3 for an average of 7-7 miles 



to the east. 

 In Experiment X., 5 travelled an average of 8-9 miles west, and 2 a mean of 10 miles east. 



It will be observed that of the 600 plaice about which particulars exist, 268, or 



