Mr. W. Thompson's Notes on British Char. 441 



species, and likewise the S. alpinus and $. Salvelinus of Do- 

 novan's British Fishes*. On thus rinding that a small loch 

 produced the two supposed species, and that the examples 

 were of different sexes, I endeavoured to procure a number of 

 individuals for the purpose of ascertaining if the difference 

 were sexual ; but this fish is taken during so short a period, 

 that in this object I was disappointed for that year. In a 

 letter upon the subject from James Stewart, Esq., of Cairns- 

 mere, Newtown-Stewart (Wigtonshire), to Capt. Fayrer, 

 dated Nov. 1, 1836, it was observed — " I lost no time in des- 

 patching my men early yesterday morning to Loch Gran- 

 noch, though I must confess with very slight hopes of suc- 

 cess in the object of their pursuit. The Char are never found 

 in our lakes before about the 13th October, and in ten days 

 again they disappear — the whole produce of the day's exer- 

 tions amounted only to four very small fish." These w T ere not 

 considered worth sending forward. The object of the inquiry 

 being made known to this gentleman, he at the same time 

 remarked — " If my evidence is worth anything, I can give it 

 with great confidence as to the Red Char \_S. Salvelinus, Don.] 

 being the male, and the Gray the female \_S. alpinus, Don.] of 

 the same species. I have noticed them frequently, when taken 

 out of the water, eject the milt and roe, and never saw the 

 former from a gray, or the latter from a red fish." I subse- 

 quently availed myself of Mr. Stewart's kindness in offering 

 to procure specimens. On the 17th of October, 1838, "a 

 dozen of the red and the same number of the gray fish," caught 

 late that day in Loch Grannoch, were sent me by this gen- 

 tleman, and being packed with great care, reached Belfast in 

 excellent condition for examination on the morning of the 

 20th — the following observations were then made upon them. 



These two dozen specimens — of the full size produced in 

 this lake — are all from 7 to 8 inches in length, and the fe- 

 males generally somewhat shorter than the males. The dif- 

 ference in form between the sexes (as proved by dissection), 

 both generally and particularly, is very great. The dorsal and 

 ventral profile of the male fish are alike, the slope being si- 

 milar from head to tail above and below : the female has the 

 dorsal line much straighter, and the ventral much more con- 

 vex than the male — a difference to be expected at the spawn- 

 ing season, and which would be less conspicuous at other 

 times. The lower jaw of some of the males is slightly turned 



* At the Meeting of the British Association held at Newcastle in 1838, 

 the two examples from Loch Grannoch were shown to my friends Mr. Yar- 

 rell and Mr. Jenyns, both of whom looked upon them as representing their 

 two species. 



