VARIETIES OF TROUT. 73 



the variety of dogs, which may all be referred 

 to one primitive type.* 



PHYS. I am somewhat amused at your 

 idea of the change produced in the species of 

 trout by the formation of particular charac- 

 ters by particular accidents, and their here- 

 ditary transmission. It reminds me of the 

 ingenious but somewhat unsound views of 

 Darwin on the same subject. 



HAL. I will not allow you to assimilate 

 my views to those of an author, who, however 

 ingenious, is far too speculative ; whose poetry 

 has always appeared to me weak philosophy, 



* I have known the number of spines in the pectoral 

 fins different, in different varieties of trout; I have 

 seen them 12, 13, and 14: but the anal fin always, I 

 believe, contains 11 spines, the dorsal 12 or 13, the 

 ventral 9, and the caudal 21. The smallest brook trout, 

 when well and copiously fed, will increase in stews to 

 four or five pounds in weight, but never attains the 

 size or characters of lake trout. 



Mr. Tonkin of Polgaron put some small river trout, 

 2 J inches in length, into a newly-made pond. He took 

 some of these out the second year, and they were above 

 12 inches in length; the third year, he took one out 

 that was 16 inches; and the fourth year, one of 25 

 inches : this was in 1734. (Carew's Survey of Cornwall, 

 p, 87. Lord de Dunstanville's edition.) 



