254 LETTER FROM PROF. LESSON A. [-'^P''- 23, 



thirdly, believing in the published statements and experiments of 

 several trustworthy authorities ; fourthly, because the fact of an 

 arrest of growth under certain conditions is one consistent with the 

 history of the development of the species. 



On the other hand. Dr. Giinther expressly affirms : — First, that 

 they are not true Salmon. Secondly, that he cannot venture to 

 give an opinion of what species they may be. Thirdly, he suggests 

 they are hybrids, but is ignorant of the parentage. 



Now, as the whole matter is one involving laws of the highest 

 consequence, I have endeavoured to follow out the objections as well 

 as circumstances favourable to the assumed facts. 



I trust I have now drawn attention to a question which, negatived 

 by some, upheld by others, still requires careful observations— ob- 

 servations and study different from what heretofore have been given 

 to it, inasmuch as the deductions consequent on the fact of an arrest 

 seem to me to be of high value in elucidating, or, as Dr. Giinther 

 says, " finding a way through this vast labyrinth of variation of 

 character in the Salmonidts" * . 



The longer I consider the question the wider the generalization 

 of law seems to grow. Imagine some sudden convulsion, and a 

 river is converted into an inland lake. Would the Salmon revert to 

 the Trout ? 



We can, indeed, conceive such remarkable changes. Is, after all, 

 species dependent on the variation and changes of old mother 

 earth? or is "natural selection" that which circumscribes the limits 

 specifically ? 



These and many such problems seem wrapped up, or are in some 

 way connected with, such strange physiological anomalies as are 

 found in this Salmon question. To my mind they have a significance 

 in zoological science far beyond that of mere demonstration of points 

 indicating specific difference. 



Aprir23, 1868. 

 W. H. Flower, Esq., F.R.S., in the Chair. 



Dr. J. Murie read the first part of a memoir on the anatomy of 

 the Sea-Bear {Of aria), founded on the animal recently living in the 

 Society's Menagerie. 



This paper will be published in the Society's ' Transactions.' ' 



Mr. St. George Mivart read the following notes on Salamandrina 

 perspicillata, communicated to him by Prof. Lessona of Turin : — 

 " La Salamandrinn perspicillata est commune aux environs de 

 * Loc. cif. Preface. 



