Royal Society, 205 



there can be no doubt that Potamogeton jiahellatus, Bab., is what 

 Chamisso and Schlechtendal consider the common form of P. pecti- 

 natus :" is it impertinent to ask whether they have ever seen 

 Mr. Babington's plant at all ? Again, have they any reason to be- 

 lieve that Carex Davalliana has been again found near Bath ? It 

 seems unquestionable that the former station was destroyed long ago, 

 but it is here spoken of as if still existing. Once more, may we sug- 

 gest that the remarks on the varieties oi Asplenium filix-fonnina re- 

 quire correction ? there is now an inextricable confusion of the pre- 

 sent and the former wording. 



We ought not to close this notice without again bearing witness to 

 the richness of knowledge and courtesy of tone which distinguish 

 the ' British Flora.' It may not be of absolute authority on contro- 

 verted questions : but, besides acting as a useful check on those 

 whose faults are of an opposite tendency, it supplies a large fund of 

 valuable information not otherwise accessible. 



PROCEEDINGS OF LEARNED SOCIETIES. 



ROYAL SOCIETY. 



April 26, 1855. — Sir Benjamin Brodie, Bart., V.P., in the Chair. 



" Some Observations on the Ova of the Salmon, in relation to 

 the distribution of Species ; in a letter addressed to Charles Darwin, 

 Esq., M.A., V.P.R.S. &c." By John Davy, M,D., F.R.SS. Lond. 

 & Edinb. 



In this paper the author describes a series of experiments on the 

 ova of the Salmon, made with the intent of ascertaining their power 

 of endurance under a variety of circumstances without loss of life, 

 with the expectation suggested by Mr. Darwin, that the results might 

 possibly throw some light on the geographical distribution of fishes. 



The details of the experiments are given in five sections. The 

 results obtained were the following : — 



1 . That the ova of the Salmon in their advanced stage can be ex- 

 posed only for a short time to the air if dry, at ordinary tempera- 

 tures, without loss of life ; but for a considerable time, if the tempe- 

 rature be low, and if the air be moist ; the limit in the former case 

 not having exceeded an hour, whilst in the latter it has exceeded 

 many hours. 



2. That the vitality of the ova was as well preserved in air satu- 

 rated with moisture, as it would have been had they been in water. 



3. That the ova may be included in ice without loss of vitality, 

 provided the temperature is not so low as to freeze them. 



4. That the ova, and also the fry recently produced, can bear for 

 some time a temperature of about 80° or 82° in water, without 

 materially suiFering; but not without loss of life, if raised above 84° 

 or 85°. 



5. That the ova and young fry are speedily killed by a solution 



