APPENDIX 157 
It will be noticed from a study of the table that 
“blacktails” are recaptured both as whitling and as 
bull-trout, but that fish marked as representatives of 
either of these latter stages are in each case recaptured 
as whitling and bull-trout respectively. That is to say, 
so far as the table shows, a whitling does not become a 
bull-trout, even, as in the case of the first fish men- 
tioned on the list, after an interval of about a year and 
ten months. The fish referred to seems, on recapture, 
to have weighed 24 lb., and may therefore be more 
correctly described as a sea trout. We may perhaps 
fairly infer from this result of marking ‘ blacktails ” 
that the young stages of the bull-trout and of the 
whitling were indistinguishable to the observer who 
conducted the marking, or are practically indis- 
tinguishable. 
Another fish worthy of special remark is the last on 
the list, a grilse which on being captured after an 
interval of six months is still described as a grilse, and 
has gained 4} lb. in weight. From the date of mark- 
ing we may infer that the fish was a kelt, and that we 
are dealing with a minimum fresh water weight as 
contrasted with a weight after feeding. 
1873, The Tweed Committee conducted further marking observa- 
tions. The results, published as a special report in 
1875, deal almost exclusively with “blacktails” re- 
captured as blacktails and whitling. The only excep- 
tions are two grilse recaptured as grilse kelts before 
leaving the river. 
