646 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Trenching. By the Duke of Bedford, K.G., F.R.S., and Spencer 

 U. Pickering, M.A., F.R.S. (Wohurn, i^th Rep., 1914, pp. 33-36). — 

 Deals further (see 5th and 9th Reports) with the bastard trenching 

 of arable land without the addition of manure or other matter, and 

 the same conclusion is arrived at, namely, that on the average the 

 effect is insignificant and practically nil. — A . P. 



Variability in Stellaria graminea. By A. S. Home {New 

 Phyt. vol. xiii. No. 3, pp. 73-82 ; 2 figs.). — ^The author describes some 

 interesting variations in the flower of Stellaria graminea, studied mainly 

 in an uncultivated field at the R.H.S. Gardens at Wisley. He found 

 that the corollas of hermaphrodite individuals varied in size, whereas 

 those of male-sterile individuals did not vary in this manner ; on being 

 transferred to a different and artificial environment the corollas of the 

 hermaphrodites diminished in size, whereas those of the male-steriles 

 showed no change. Individuals of all grades were found varying with 

 respect to the following characters : long and short petals, wide and 

 narrow petal-lobes, long and short stamens, fertile and sterile stamens. 

 Femaleness is usually associated with corollas of small or medium size, 

 never with corollas of the largest size, while hermaphroditism is usually 

 associated with corollas ranging from medium to large size. Inter- 

 mediate individuals were found with some stamens resembling those of 

 hermaphrodite individuals and others resembling those of male-sterile 

 individuals ; such individuals had medium-sized corollas ; hence 

 individuals with a corolla of medium size may be either hermaphro- 

 dite or male-sterile, or belong to the intermediate series. The author 

 suggests a working theory to explain these phenomena. It is possible 

 to sort out from the plexus forms which are definitely male-sterile 

 and hermaphrodite respectively ; individuals of both kinds set good 

 seed, and hence have probably been pollinated. The hermaphrodite 

 individuals cross-pollinate among themselves, since the flowers cannot 

 of course receive pollen from male-steriles ; but the latter, if pollinated, 

 receive pollen from hermaphrodite individuals, hence the conditions 

 obtain for Mendehan hybridization. The author relates his observa- 

 tions with those made by de Vries and Gates on Oenothera and by Sala- 

 man on the Potato, and promises further experimental work. — F. C. 



Vegetation in Mountain Valleys. By Francis Ramaley {Bot. 

 Gaz. Ivii. pp. 526-528, June 1914). — The author found that in a 

 small glaciated valley, at 9000 feet altitude in the Rocky Mountains, 

 the percentage of ground bare of living or dead vegetation showed 

 great variation at different seasons. 



Thus on May 30 from 50 to 80 per cent, of the ground in dry grass- 

 land was bare in seventeen selected squares. 



The growth of the new vegetation had by June 28 or July 12 

 resulted in covering all except from 10 to 20 per cent, of the ground. 



When meadow grassland was examined in the same way, it was 

 found that in May only 25 to 45 per cent, was free of plants, and on 



