/ 



424! ^ Zoological Society : — 



of December, when in the living ova the circulation was distinct 

 under the microscope, and the embryos were visible even to the 

 unaided eye, I examined the whole number then remaining, viz. 405, 

 thus reduced, owing to 6/ having been removed, one after another 

 having become opaque, and 1.52 having been taken out for the pur- 

 pose of experiments. Of these 405 remaining, 138 were found alive, 

 each containing a well-formed embryo, and 267, though still trans- 

 parent, vdthout life, no marks of organization being to be seen in 

 them, either with the naked eye or under the microscope. Hence, 

 irrespective of the 152 experimented on, the proportion of living to 

 dead on the 14th of December would appear to be as 138 to 364, 

 or about 25 per cent. And, with the exception of two which died 

 after the 14tb, all those then alive were hatched, the first on the 

 31st of the same month, the last on the 9th of January. 



What are the conclusions to be drawn from these results ? From 

 those of the first series of experiments, may it not be considered as 

 proved that the power of resisting an undue increase of temperature 

 is possessed in a higher degree by the ova in an advanced than in an 

 early stage of development, — the degree probably being in the ratio 

 of the age ? From those of the second series, is it not as manifest 

 that the power of bearing distant transport, and of retaining life in 

 moist air, is in like degree increasing with age ? And from both, 

 may not the general conclusion be drawn, that the strength of vi- 

 tality of the impregnated ovum, or its power of resisting agencies 

 unfavourable to its life, gradually increases with age and the progress 

 of fcetal development ? And as the Charr is one of the most delicate 

 of the family of fishes to which it belongs, may it not further be 

 inferred, with tolerable confidence, that the ova of the other and 

 more hardy species of the Salmonidee, were they similarly experi- 

 mented upon, would afford like results, confirmatory of those ob- 

 tained last year in some trials on the ova of the Salmon, and men- 

 tioned in my former letter to you ? 



The practical application of these results, and of the conclusions 

 deducible from them, is obvious, and need not at present be dwelt 

 upon. 



1 am, my dear Sir, yovxrs very truly, 



John Davy. 



Lesketh How, Ambleside, 

 January 10, 1856. 



ZOOLOGICAL SOCIETY, 



January 9, 1855. — Dr. Gray, Vice-President, in the Chair. 



Notice of the Horns of an unrecorded Species of Prong 

 Horn (Antilocapra), in the Collection of the Derby 

 Museum, Liverpool. By Dr. John Edward Gray, F.R.S., 



V.P.Z.S. ETC. 



Some years ago the late Earl of Derby showed me a pair of horns 

 attached together by the skin of the forehead, which he had then 



