54 THE SALMON. 



old smolts that left the pond had descended to the sea, 

 and that their residence there extended to only a few 

 weeks. But probably because this point did not in- 

 volve the chief or primary object of the experiments 

 care was not taken at first to manage so as to bring 

 about anything that can be safely regarded as a decision. 

 Of the smolts that left the pond the first year, between 

 1200 and 1300 were marked by cutting the second 

 dorsal fin, and of these 2 2 are stated to have been caught 

 as grilse that same season ; of those that left the pond 

 the second year, 1135 were marked by cutting the tail, 

 and of these " several" are reported to have been caught 

 as grilse in the course of their season ; and Mr. Buist has 

 reported similar results in more recent years. Such facts 

 must of course reckon as something ; but there are several 

 serious deficiencies in the evidence on that side, and 

 some very formidable facts on the other. No firm faith 

 can be placed in the system of marking by cuts any 

 one that, by examining the heaps of fish as they are 

 tumbled from the nets, or by any other means, has had 

 an opportunity of observing the great number and in- 

 finite variety of marks and maimings produced for the 

 most part, it would appear, from encounters with marine 

 enemies, will have a strong distrust of any such tests. 

 It is not enough, we submit, that out of the 30,000 or 

 40,000 grilse caught in the Tay in 1855, twenty-two 

 had an abscission on a certain fin, such as was inflicted 

 on 1100 of the smolts of that year; it might perhaps 

 have been as possible to find among the 40,000 twenty-! 

 two individuals with a cut on their tails similar to that 

 which was not inflicted on the smolts till the next year. 



