NOTES AND ABSTRACTS. 



815 



were early-flowering than late. It is clear, however, that further ex- 

 periment is necessary to establish the apparent fact of genetic coup- 

 ling in this relation, for there are many known exceptions, but 

 these on closer investigation may resolve themselves. It would appear, 

 however, that lateness and earliness of flowering in peas are connected 

 in some w^ay with the length and thickness of the internodes. — F. J. C. 



Pelargroniums and Artificial Manures. By 0. Glaser 

 [Gartenflora, vol. lix. pt. x. pp. 226-228; 3 figs.). — Pot plants benefit 

 by the careful addition of Chili saltpetre, potash, and superphosphate. 

 Ammonium sulphate is also beneficial. — S. E. W. 



Pelargoniums, Diseased. By L. Peters (Gartenflora, vol. lix. 

 pt. x. pp. 209-213 ; 1 plate). — Pelargoniums are frequently attacked 

 by the fungus Pytliiuni Debaryanuni with fatal results. — S. E. W. 



Pentstemon Hartwegrii (Garden, Jan. 1, 1910, p. 2),— This 

 plant as figured by Lindley in 1838 in the " Botanical Eegister, t. 3, 

 under the name of P. gentianoides, is stated to differ hardly, if at all, 

 from the well-known variety, ' Newbury Gem.' — H. R. D. 



Petroleum : Its Action on the Development of Plants. By 



F. Kryz (Zeitschr. /. Pfla?ize7ikrank. xix. 1909, Heft 8. p. 449).-— 

 Petroleum in the form of an emulsion with water is used as an insecti- 

 cide on plants without serious injury to them. The author's object 

 was to ascertain the action of petroleum when taken in by the roots 

 of plants. Datura Stranioniuni L. and AUsina Plantago L. were the 

 plants used, and they were watered with petroleum-water mixtures of 

 different strengths. It was found that the petroleum was taken in by 

 the plants and deposited in unaltered condition in the various tissues. 

 It does not act as a direct poison, but when it accumulates in the plant 

 in sufficient quantity, the normal processes of nutrition, growth, &c., 

 are interfered with to such an extent that the plants ultimately 

 succumb. Introduced into the soil, petroleum causes the latter to 

 become physically and physiologically dry, so that growth is inhibited. 

 As further showing that petroleum is not a poison to plants, it was 

 found that its addition to fermenting yeast did not retard the activity 

 of the fermentation. — G, H. P. 



Philadelphus Delavayi (Bot. Mag. tab. 8324).— Nat. ord. 

 Saxifragaceae ; tribe Hydrangeae. Western China. Shrub, 3-15 feet 

 high; leaves ovate or oblong lanceolate, 3 inches long; flowers white, 

 1 inch across. — G. H. 



Philodendrons. By P. Tutenberg (Gartenflora, vol. lix. pt. i. 

 pp. 22-24; 2 figs.). — Philodendron hastatmn., P. imperiale var. 

 Laucheanmn, P. eruhescens, and P. Warcsewiczii are admirably adapted 

 for growing up pillars in a winter garden. — S. E. W. 



Phoenix canariensis at Hyferes, Cultivation of and Trade in. 



I By M. J. Fonssat (Jour. Soc. Nat. Hart. Fr. ser. iv. vol. xi. p. 368; 



