PHAITEROaAMIA. 453 



and unpeeled potatoes and apples, instituted with a view to de- 

 tex'miue whether living and dead tissues are alike aiFected when 

 exposed to evaporation, or diversely, and to what extent. In 

 order to kill the tissues they were exposed to frost ; the kinds 

 of apple, however, submitted to experiment were not affected by 

 it. Potatoes and apples were selected on account of the cork- 

 cells of their superficial layers, which prevent rapid evaporation 

 and enable the tissues to retain vitality some time after separation 

 from the parent plant. 



Naegeli, C. — Ueber die "VVirkung des Erostes auf die Pflanzenzellen. 

 p. 246. 



Upon the questions (1), Are there cells the fluids of which 

 may be frozen without detriment to vitality?, and (2), Wliat 

 alterations does frost occasion in the cell-membrane and contents ? 



Naudin, M. — Sur les Plantes hybrides. Kev. Hort. 1861. 396. 



M. Naudin considers hybrid plants more frequently fertile 

 than sterile. Petunia violacea and P. nyctaginiflora two species 

 which are perfectly stable when fertilized by their own pollen, 

 may be easily hybridized, yielding intermediate forms, closely 

 resembling each other, and as fertile as theii* parents. Naudiu's 

 experiments generally establish the fact that hybrids of the first 

 generation are very uniform ; the second and subsequent gene- 

 rations show, however, great inconstancy. Of 47 plants raised 

 from a hybrid between the above species of Petunia, but one 

 repeated its parent. 



NiTSCHKE, Th. — Morphologie des Blattes von Drosera rotundifolia, 

 L. Bot. Zeit. 1861. p. 145. 



Einige Bemerkungen zu meinem Aufsatze : " Morphologie 



des Blattes von Drosera rotundifolia, L." uud des Herrn Prof. 

 Caspary Beurtheilung desselben. Bot. Zeit. 1861. p. 221. 



Anatomie des Sonnenthau-blattes {Drosera rotundifolia, L.) 



Bot. Zeit. 1861. pp. 233, 241, 252. With 1 plate. 



Wider des H. Prof. Caspary neuste Polemik gegen meine 



Aufsatze iiber Drosera rotundifolia, L. Bot. Zeit. 1861. 308. 



NoEMAJT, A. M. — Notes on the Botany of the South Durham Bal- 

 last Hills in the year 1861. Trans. Tyneside Nat. Club. v. 136. 



— — — On the Species into which the Linnean Polygonum avicu- 

 lare has been divided by Continental Botanists, ibid. 140. 



CErsted, a. S. — Til Belysning af Slaegten Viburnum. Vidensk. 

 Medd. 1860. Ext. pp. 38. With 2 plates. 



A monograph of the Linnean genus Viburnum, here treated 

 as a tribe of Sambuceae, and broken up into five genera, Oi'eino- 

 tinus (America), Microtinus (Himalaya, China), Solenotinus 

 (India), Fiburnum and Times. 



Oliyee, Daniel. — The Natural Order Aurantiaeeae, with a Synopsis 

 of the Indian Species. Linn. Proc. Suppl. Vol. v. (Bot.) p. 1. 



The species of Sclerostylis of Dr. Wight and Triphasia mono- 

 pylla are referred to Atalantia, Sclerostylis being suppressed. 



