The Salmon 
beforehand from a study of the scales of fish, which I will endeavour 
to explain in a later chapter dealing with scales, 
On 
What has been said of the marked fish may be put in a con- 
densed form as follows. The fry which were hatched in March 1903 
became smolts in April 1905, and migrated to the sea in April and 
May 1905 at the age of two years. The first run of these returned 
to the river as grilse weighing from 14 to 12 or 13 lbs., from the last 

Fic. 11.—Stormontfield Ponds on the Tay, erected 1852. 
week in May till the end of December 1906. The second run 
continued to come from the middle of December 1906 to the middle 
of June 1907, and weighed from 6 to 13 lbs. The third run returned 
from the middle of July 1907 to the end of December, and weighed 
from 12 to 30 lbs. The fourth run extended from the middle of 
October 1907 to the end of May 1908, and weighed from 13 to 38 and 
occasionally 4o lbs. The average weight was about 20 lbs., but it 
varies a pound or two from year to year. The fifth run came on in 
