362 



time of their receipt, I was unaware of the value which attaches to a 

 'direction/ 'post-mark,' &c., and, in my ignorance, I tore away, in 

 a few instances, these important aids to proof of authenticity. 



" Accompanying this note and the above collection is one of the 

 balls of ' elastic substance,' mentioned by Sir Joseph Banks in a 

 communication to my great-grandfather. Should the Royal Society 

 deem this, too, worthy of being in their possession, I shall have much 



pleasure hi their accepting it. 



" I am, dear Sir, 



" To C. R. Weld, Esq., " Yours very truly, 



Royal Society." " EDWIN CANTON." 



" P.S. In thanking you, Sir, for your suggestion that I should be- 

 queath the letters, &c. to the Royal Society, I beg to say that I shall 

 feel myself much gratified in finding the present to be one which 

 they will now do me the honour of accepting ; and in conclusion, 

 may I beg that you will oblige me by retaining, yourself, the seal, 

 in which you take an interest ? " 



II. " 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.ft.S. &c." By JOHN 

 DAVY, M.D., F.R.SS. Lond. & Edinb., Inspector-General 

 of Army Hospitals. Received March 27, 1855. 



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 



