1868.] DR. J. MURIE ON SALMO SALAR. 213 



zontal bend, though going backwards on the carina to a variable ex- 

 tent. Now as to the bronchial tubes : I am not certain that the 

 observation I make on the specimens occurring to me is reconcile- 

 able with Yarrell's figure in the ' Linnean Transactions,' vol. xvii. 1, 

 but I always find C. pass77ioriv/ith the two tubes separate, the swelling 

 of the lower portion comparatively small, and the directions of the 

 tubes nearly parallel, whilst in O. buccinator the swelling of the 

 lower portion is much greater, causing the narrow tubular portions 

 to recede widely ; and 1 think the difference in the breadth and figure 

 of the tracheal rings holds good as I described it. 



"As to the matter of size, my very young C. buccinator was larger 

 than any C. passmori I have seen ; and though yours are smaller, 

 though evidently older than the one I refer to, I think confinement 

 and being captui'cd very young may account for this difference. 

 Without doubt the ordinary size and weight of those the sternum of 

 which marks them as passmori is much less than that of the others. 

 The other characters 1 gave may have value, but I wait for further 

 observations. I take my stand on the sternum ; and now with three 

 specimens of each species before me exhibiting varying development, 

 but the same essential distinction, and affording proof that it is not 

 a distinction of sex, I feel bound to maintain my species, though I 

 will give it up on a reasonable explanation of facts. You have not 

 yet had all the facts before you, not being aware of my young male 

 Trumpeter with the parts in an early stage of progress, yet showing 

 a manifest difference from the seemingly mature C. passmori, and 

 putting an end to the notion of the form in C. passmori being a 

 stage of progress. I am, &c. 



" P.S. On looking again at your paper I fear I did not make my 

 measuring sufficiently clear in one point, as you seem to have mis- 

 apprehended me. 1 refer to your page numbered 12, the short 

 paragraph near the middle of the page, respecting the sterno-tracheal 

 elevations in your specimens as compared with mine. Now in my 

 specimen of C. passmori and in both the other specimens which I 

 now think belong to it, noticed in my appended letter, the inner 

 surface of the sternum is level ; there is no bony elevation, except 

 that at the front of the sternum forming a knob. There is no hori- 

 zontal loop of the trachea in any specimen which I should call G. 

 passmori. My present doubts all arise from Yarrell's figure in the 

 ' Linnean Transactions,' vol. xvii. The bronchial tubes there are 

 certainly those of C. buccinator ; and perhaps his figure is drawn 

 from a very young specimen of C. buccinator, as they generally 

 attain great size when young, and in that state the horizontal loop 

 could be only just commencing. I shall be on the look-out for fur- 

 ther information ; but 1 believe we shall have no Swans this season." 



Dr. J. Murie exhibited some specimens of fishes illustrative of the 

 supposed arrest of development of the Salmon (Salmo salar) when 

 retained in fresh water. These examples had been hatched in the 

 Society's Fish-house from ova presented by Mr. F. Buckland, in 



