502 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Peach Leaf-curl, Spraying for. By D. Reddick and L. A. Toan (U.S. A. 
Exp. Stn., Cornell, Cir. 31, Sept. 1915, pp. 65-73; 1 fig.). — A number of 
substances applied as a dormant spray will give perfect control of peach leaf- 
curl, provided every bud on the tree is covered with the material. The best 
spraying solution is undoubtedly lime-sulphur if applied in the autumn. The 
author details a number of spraying experiments with the lime-sulphur in the 
proportion of 1 to 8, at various stations in New York State, in which the results 
have proved to be highly satisfactory in checking the ravages of Exoascus 
deformans, the causal organism of the peach leaf-curl. — A. B. 
Peach Leaf Glands. By C. T. Gregory (U.S.A. Exp. Stn., Cornell, Bull. 
365, 24 pp. ; 9 plates). — A study of the taxonomic value of glands of Peach 
leaves. While adding no new facts generally, it is an interesting survey of the 
question, treating the histological side in an able manner. — E. A. Bd. 
Peas, Sweet, in Winter. By H. Theulier (Rev. Hort. Oct. 16, 1915). — Advice 
on treatment. — C. T. D. 
Pectins of Cider Apples and their Uses. By B. T. P. Barker (Ann. Rep. 
Agr. Res. Stn., Long Ashton, 1915, p. 56). — The pectins, which are the chief 
constituents of jellies formed from fruits, have been examined by the author in 
the case of the apple, who finds that gelling does not occur unless a certain pro- 
portion of sugar and of acid, such as tartaric acid, is in the fruit j uice . Concentration 
by boiling does not alone bring about the formation of " gel," and the failure 
of jam to set may be due either to the presence of insufficient pectin, or sugar, or 
acid. — F. /. C. 
Pegomyia hyoscyami, Notes on. By E. N. Cory (Jour. Econ. Entom. vol. ix. 
p. 372, June 1 91 6 ; figs.). — This insect, which mines the leaves of henbane (see 
p. 139), also attacks spinach, goosefoot (Chenopodium album), and species of Ama- 
rantaceae (e.g. Amaranthus retroflexus). Three broods apparently occur during 
the year. No measures of control were attempted. — F. J. C. 
Pentstemons, Hybrid. By S. Mottet (Rev. Hort. March 16, 191 6 ; coloured 
plate). — Description and illustration of large-flowered Pentstemons. — C. T. D. 
Pentstemon rupicola (Bot. Mag. t. 8660). — North America. Nat. Ord. 
Scrophulariaceae, tribe Cheloneae. Herb, dwarf, prostrate and branching at 
the base, rosette-like in form, 3 inches across. Leaves \ inch long, opposite 
and crowded below. Corolla, \\ inch long, carmine. — G. H. 
Pests, Fruit. By P. Lesne (Rev. Hort. May 16, 1916, June 16, 1916). — 
Coloured plate showing a number of insects which attack fruits. — C. T. D. 
Phaseolus vulgaris, Genetic Study of. By R. A. Emerson (U.S.A. Exp. Stn., 
Nebraska, Bull. 7, 73 pp. ; 16 figs, and tables). — A close and detailed study of 
inheritance in dwarf and tall beans. The author adopts the assumption of 
inequality in dominance and potency of some of the factors concerned. — E. A . Bd. 
Phlox Drummondii, Colour Varieties of. By J. P. Kelly (Jour. N.Y. Bot. 
Gard. xvi. pp. 179-191 ; Sept. 1915). — About two hundred varieties of Phlox 
Drummondii have arisen during the seventy-nine years since its introduction 
to cultivation as a little- varying plant in 1835. The history of the varieties is 
traced by the author and references to literature are given. — F. J. C. 
Phosphorus in Plant and Animal Substances, Studies on the Estimation of 
Inorganic. By E. B. Forbes, F. M. Beegkv and A. F. D. Wussow (U.S.A. 
Exp. Stn., Ohio, Tech. Bull. 8, June 1915, pp. 1-48). — When studying the meta- 
bolism of plants and animals, it is frequently desired to distinguish between 
simple inorganic phosphates and phosphorus in combination with organic groups. 
Two different methods, one for plants, the other for animal substances, were 
described in Ohio Bull. 215, 1911, and the present bulletin is an extension of work 
and improvement in the methods there set forth. — A . B. 
Phytophthora infestans occurring in Tomatos. By S. P. Wiltshire (Ann. 
Rep. Agr. Res. Stn., Long Ashton, 1915, p. 92). — The common potato- 
disease fungus Phytophthora infestans was found on tomatos at Long Ashton, 
and the opportunity pi comparing the infectivity of spores of the fungus from 
potato and tomato respectively was taken. The spores from the potato readily 
infected the potato, but in no case did they infect the tomato. The spores from 
the tomato readily infected the tomato, but in only a few cases were potatos 
