54 



As to the last reason, " 54 pyloric appendages," as I had 

 not dissected the fish I was, of course, unaware of the number, 

 which I now find, is three or four less than in the first grilse- 

 and 13 or 14 less than in some others of the Derwent 

 salmonoids. Nevertheless I should have regarded the number 

 64 (having no other light than Dr. Gunther's own descriptions), 

 as a proof of the fish being a true salmon, because the 

 Dr. gives as his own formula for salmo salar, " Coec. pylor., 

 63 to 77," and also mentions a mature male from the River 

 Tamar in which the Pyloric appendages were only 51. Again 

 Dr. Giinther's formula for salmon trout is "49 to 61, rarely 

 less," but in the descriptions of salmon trout in the British 

 Museum, out of 20 specimens seven contain the minimum 

 number 49 or less ; six more contain less than the number 

 found in the second grilse ; while the average number in 

 the remaining seven only slightly exceeds 54. On the 

 strength of this test, therefore, Ave should be justified in 

 regarding the second grilse as a true salmon. 



Dr. Giinther speaks of the rapid growth of salmonoids in 

 our waters, and attributes it to the presence of the anchovies, 

 but it is at least doubtful whether the fish would thrive 

 better here on anchovies than in Britain on whitebait, 

 sprats, herrings, or others of the schoolfish abounding on the 

 coast. If the first and second grilse could be regarded as 

 true salmon, nothing extraordinary could be found in their 

 size, as it is about the average of grilse taken in spring on 

 their first journey from sea. But the case is very different 

 if they are salmon trout, — because the majority of salmon 

 trout on the first return from sea do not weigh more on an 

 average than from one pound to one pound and a half. That 

 the first and second grilse were on their first journey from sea 

 is all but certain from the presence of several of the deciduous 

 teeth still left on the vomer, and the fact that they should 

 both so much exceed the average weight of a large majority 

 of the salmon trout of a similar age from the best British, 

 rivers, is difficult to explain if they are salmon trout. 



Had Dr. Giinther been able to examine the first smolt 

 sent from this colony in 1869 by the light which the further 

 conduct of the experiment has since thrown on the subject, 

 we should never have been told that that smolt was a stunted 

 salmon trout, because the statement that it was stunted was 

 due to an erroneous conviction that no migratory salmon could 

 return from the sea to a Tasmanian river, and that as we 

 had only received one lot of ova of salmon trout in 1865, the 

 smolt must have been thi'ee years and-a-half old. The deter- 

 mination of the species of the second grilse proves that the 

 first smolt was no stunted individual ; but that it was what 



