Linnaan Society. 471 



racter to the scenery. Mr. Fox's collections from Buenos Ayres and 

 Uruguay include five species of Mimosa, one of Desmanthus, two of 

 Calliandra. and five of Acacia ; yet none of these are so abundant as 

 to form characteristic features of the country. There are several spe- 

 cies of Cassia natives of Buenos Ayres ; but the magnificent Poin- 

 ciana Gilliesii, although well established on the banks of the Plata, is 

 said not to be indigenous. Daubentonia punicea was found by Mr. 

 Fox to grow wild sparingly on the bank of the Plata below Buenos 

 Ayres, and in great abundance and beauty on the banks of the Uru- 

 guay near its mouth ; and Mr. Bunbury thinks it quite possible that 

 Cavanilles, who only saw it in a Botanic Garden, may have been 

 misinformed as to its native country, which he states to be " New 

 Spain," although it is also possible that it may be common to both. 

 Several European species are naturalized at Buenos Ayres, such as 

 Medicago sativa, M. denticulata, Trifoliwn repens, and Melilotus par- 

 vifiora. Indigofera Anil, apparently general throughout the hotter 

 parts of America, was observed by Mr. Fox to be common all through 

 South Brasn and the Banda Oriental, but not to occur south of the 

 Rio de la Plata, ^schynoinene ciliata ranges at least from Guiana 

 to Buenos Ayres, and, as Mr. Bentham observes, is scarcely distin- 

 guishable from the North American yE. hispida, which is found as far 

 north as Philadelphia ; and another jEschynomene from Buenos Ayres 

 seems to agree with ^. conferta from British Guiana. 



June 7. — Thomas BeU, Esq., President, in the Chair. 



Mr. Yarrell, V.P.L.S., exhibited a specimen of the Dusky Petrel 

 (Pujftnus obscurus of modern authors). This bird, new to the 

 British Islands, flew on board a small sloop, off the Island of Va- 

 leutia, on the south coast of Ireland, on the evening of the 11th of 

 May last. The species having been frequently confounded with the 

 Manx Petrel {Pitffinus Angloruni), from their close resemblance in 

 plumage, a specimen of the Manx Petrel, together with the eggs of 

 both, was also exhibited for comparison. 



Mr. Hogg, F.L.S., exhibited specimens of an umbellate variety of 

 the common Primrose {Primula vulgaris, var. /3. of Smith's ' English 

 Flora'), gathered in Thorp Wood, near Stockton-upon-Tees, on the 

 r2th of May in the present year. 



Read some Notes " On the Artificial Breeding of Salmon and 

 Trout, with Remarks on the Modes of Fecundating their Ova." By 

 John Hogg, Esq., M.A., F.R.S., F.L.S. &c. 



After referring to his notice of the artificial breeding of Salmon, 

 as practised by Mr. Isaac Fisher, read before the Society on the 4th 

 of May last, and of which an abstract is given in the ' Proceedings,' 

 p. 178, Mr. Hogg gave an account of some further experiments by 

 the same gentleman in the River Swale, made with considerable 

 success, during the past winter and spring. A letter on this subject 

 from Mr. Fisher appeared in the York Herald, dated May 3rd, 

 1853, from which we learn that ova, placed by him on the 25th of 

 December last in a wooden box with gravel at the bottom, and 



