6 



Appendices to Tiventy -eighth Annual Report 



of hatching. In other words, a smolt, when it leaves the river for its 

 great feeding-place, the sea, may return for the first time in any one 

 of the following four seasons, though the majority seem to return 

 within three years. We have no evidence to show that the first 

 return is delayed beyond the fourth year. 



In the same wa}% we yet lack evidence to prove what nevertheless 

 may be true, that spring fish produce spring fish, or autumn fish 

 produce projeny which run at a corresponding season. In passing, I 

 may also state that we do not know as yet the proportion of smolts 

 which reach maturity under natural conditions. 



With regard to our information from marking, we know that the 

 8840 fish of which I have particulars have spawned at least once. 

 The fish have all been marked in fresh water, and we know that no 

 salmon eggs can come to fruition in the sea. The reproductive period 

 in the salmon is in all probability very much the same as in the brown 

 trout. All evidence points in this direction. It we take the repro- 

 ductive period as ceasing when the fish is about eight or nine years 

 old, we niay notice that this corresponds with the time when the fish 

 ceases to appear in our rivers, and when the salmon ceases to return 

 from the sea we cease to know anything about it. 



I have received 380 recovered marks, discounting a certain number 

 of very unimportant recaptures, such as clean fish taken a second time 

 before they had returned to the sea, kelts taken in the same way, 

 and also discounting all sea trout marked. 



If for the present purpose only such fish as were marked as kelts 

 and recaptured as clean fish be selected, we have to confine ourselves 

 to 144 records. Of these, 63 fish had adopted the long absence in the 

 sea, and 81 the short habit. 



The 144 fish were no doubt all going to spawn a second time, but 

 they are only a sixtieth of the number marked. It must not be for- 

 gotten that an unknown number of fish bearing marks are or were in 

 our rivers, and that the 144 are only a proportion of those, but none 

 the less the number is a strikingly small one. 



Of the 81 fish which returned to fresh water after a short migration 

 in the sea, it is possible that a few might have spawned a third time. 

 We have to recollect that even a marked fish is usually knocked on 

 the head, and its record thus ended. So far as our marking shows, 

 we have only one example of a fish. spawning thrice. This is the fish 

 referred to in my last year's Report as having been originally marked 

 1396, in the Helmsdale in the spring of 1905, when a kelt. It was 

 recaptured for the first time in September 1906, when a fish 

 approaching spawning condition, and the mark was changed to 2797. 

 In September 1908, when the watchers were again netting for 

 spawners in the same part of the river, the fish was again recaptured. 

 If men netting for commercial purposes, or rod fishers, had caught this 

 fish it would have been knocked on the head at the first recapture. 

 We never should have had. the information about the second, let alone 

 the third appearance in the same river. This is important, for it 

 implies that some of the fish recaptured and killed, if again set at 

 liberty, might have told the same tale, and that we are not at liberty 

 to base an argument upon the numbers of recaptured fish. 



Allowing this, we still," however, have the evidence educed by the 

 examination of the scales. The " spawning mark" is a very distinct 



