ON MALFORMED TROUT FROM SCOTTISH WATERS 101 



I extract the following passage from a letter from Mr. King to 

 Mr. Harvie- Brown commenting on this analysis, and dated 2gth 

 August 1890 : 



" The results you will notice come out very much as they did 

 before, showing the water to be one of great purity. It hardly con- 

 tains anything except a very small quantity of common salt. 



There is a little Iron Oxide present, but this I am afraid has 

 arisen from the tin vessels in which unfortunately the sample was 

 sent." 



Again, three days later, Mr. Falconer King writes to Mr. Harvie- 

 Brown : 



" As to the comparison between this Galloway water and the 

 Islay one, the great point seems to be their similarity as regards 

 freedom from lime and magnesia compounds. They both contain 

 a little common salt, but they are both exceptionally free from all 

 other salts. A man when he eats takes lime from his food, but 

 perhaps a fish is more dependent on lime in the water than in its 

 food." 



Here then we have the impure water theory refuted at once by the 

 fact that the waters best known for the production of Docked-tailed 

 Trout are, on the contrary, of most remarkable purity. And we have 

 the new theory suggested that it is this very purity which is the cause 

 of the malformation. 



But in the first place, if impurity of the water will not account 

 for the presence of Docked-tailed Trout in Loch-na-Maorachan 

 and Loch Enoch, neither will exceptional purity account for the 

 occurrence of a similar malformation in the River Carron and in 

 Gonar Burn. This is the first hitch in the theory. 



In the second place, I rather think that this paucity of lime will 

 be found more or less characteristic of all our lakes whose bed is 

 formed by ancient crystalline rock such as the quartzite and granite 

 in which Loch-na-Maorachan and Loch Enoch are respectively 

 embasined. The docked condition ought therefore to be character- 

 istic of the trout in very many more lakes in Scotland than these 

 two solitary tarns, but as yet we know of no others in which they 

 occur. 



In the third place, these fish do not suffer from rickets or any 

 disease akin to rickets so far as I can see. The extremities of the 

 rays of certain fins are malformed, but the skeleton is as well ossified 

 as in any other trout which I have ever dissected. Lime of course 

 enters into the system of the fish in some way, and what can be more 

 natural than to suppose that it exists in their food, just as it exists in 

 our own. 



I venture therefore to submit that there is as yet no evidence 

 that the chemical composition of the water has anything to do with 

 the occurrence of the Docked-tailed condition in trout. 

 2 C 



