92 



lower reaches to some extent. As a matter of fact, 

 34 had moved up, 25 had dropped lower, and the 8 

 remaining fish were found in the position in which 

 they had been marked. Only 1 fish out of the 25 

 which had dropped back was reported as having in the 

 interval of thirty-eight days gained ^ Ib. in weight, 

 and one naturally hesitates to state that with so slight 

 a change one has evidence of sea feeding and not 

 rather of inaccurate weighing. All others of this 

 series showed decreases from to 2 Ib. In the Tay 

 24 clean marked fish (spring fish) have been recap- 

 tured within short intervals. They were marked 

 between Perth and the Linn of Campsie, about nine 

 miles above Perth. Of this number 8 fish which 

 had dropped back were diseased, with one exception, 

 No. 9100. This fish was marked at the Linn, and 

 recaptured in a quite healthy condition about 13 

 miles farther down in the upper tidal waters of 

 the estuary. The interval was two months and ten 

 days, and the fish was reported as having lost 5 Ib. 

 in weight (the greatest decrease recorded for a clean 

 fish in fresh water 27 Ib. to 22 Ib.). In the interval 

 a heavy flood of snow water had occurred. Two fish 

 were found in the same position as before, and two 

 had ascended between 30 and 40 miles, while others 

 had made a less ascent. A few recent Dee recap- 

 tures of clean fish show in every case an ascent, and 

 in all but one instance an ascent to the top waters 

 of the river. In these Scottish records there seems 

 nothing to indicate any return to the sea, as has been 

 shown by Mr. Holt to occur in Ireland. 



