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February 7, 1856. 



Colonel SABINE, R.A., V.P. and Treasurer, in the Chair. 

 The following communications were read : 



I. "On the Vitality of the Ova of the Salmonidte of different 

 Ages; in a Letter addressed to CHARLES DARWIN, Esq., 

 M.A., V.P.R.S. &c." By JOHN DAVY, M.D., F.R.S. Lond. 

 and Edinb. &c. Received January 15, 1856. 



MY DEAR SIR, In a letter which I had the honour to address to 

 you last year " On the Ova of the Salmon in relation to the distri- 

 bution of Species," I have expressed the hope that some of the 

 results of observations therein described may aid in solving the 

 question as to the period, the age, at which the impregnated ova of 

 fish are most retentive of life, and consequently are in the state best 

 fitted for transport without loss of life. 



Joining with you in considering the subject in need of and deser- 

 ving further inquiry, I have taken the earliest opportunity that has 

 offered of resuming it. The experiments which I have made, and 

 which I shall now describe, have been more limited than I could 

 have wished, having been confined to the ova of the Charr, as I was 

 not able to obtain the ova of the Salmon or any of its congeners in a 

 fit state for the trials required. 



The ova of the Charr which have been the subject of my experi- 

 ments, were from living fish brought to me from the river Brathay, 

 a tributary of Windermere, on the 9th of November. They were ob- 

 tained by the pressure of the hand on the abdomen of the females 

 under water, and immediately after their expulsion a portion of liquid 

 milt, procured in the same way from a male, was mixed with them 

 for the purpose of impregnation. 



The ova thus treated, 654 in number, procured from two fish, 



VOL. VIII. D 



