200 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Peach 'Niagara.' ByU. P. Hedrick {U.S.A. Exp. Stn., Geneva, Bull. 403 ; col. 
pi.) — A handsome seedling from the well-known ' Crawford,' ripening a little 
later; probably raised in Maryland. — E. A. Bd. 
Peaches, Varieties and Classification. By H. P. Gould (U.S. Dep. Agr., 
Farmers' Bull. 65-, 13 pp.). — Lists of peaches for various States in the U.S.A., 
times of ripening &c, with a short scheme of classification upon geographical 
lines. — E. A. Bd. 
Pear Psylla, Adults and Eggs, Susceptibility to Spraying Mixtures of Hibernating. 
By H. E. Hodgkiss (U.S.A. Exp. Stn. New York, Bull. 378, May 1914; 3 plates, 
2 figs.). — Investigations show that the best means of killing the " flies " is spray- 
ing during a period of warm weather, preferably in November or December, or 
during March or early April. 
The most satisfactory mixture is f of a pint of tobacco extract (40 per cent, 
nicotine), in 100 gallons of water, to which are added 3 to 5 lb. of soap. — V. G. J. 
Pear Stock. (U.S.A. State Com. Hort. Cal. vol. iv. No. 7, July 1915 ; 10 figs.) — 
Contains an account of the blight- and insect-resisting qualities of the Chinese 
wild pear, and the suggestion that it might be very useful for stock purposes in 
California. — V. G. J. 
Phlox Drummondii, Heredity of Flower Colour in. By A. W. Gilbert 
(Jour. Agr. Res. iv. p. 293-302, July 1915 ; plates). — True types were selected 
by breeding for three years, and crossings were made with the usual precautions. 
The unit characters concerned in producing colour are described as (1) a dark 
eye factor producing dense colouration at the centre of the flower. This was 
dominant over its absence, the white eye, which was exhibited in more or less of 
a definite pattern. (2) A blue factor. (3) A red factor. (4) An intensifying 
factor which determines the degree of pigmentation of the reds. (5) A yellow 
factor which acts only in the presence of the eye factor. 
The reds and blues are cell-sap colours, and the yellow is due to yellow 
chromoplasts. — F. J. C. 
Phytophthora Infestans, Perennial Mycelium in Related Species. By I. E. 
Melhus (Jour. Agr. Res. v. pp. 59-70, Oct. 191 5 ; pi.). — The author shows 
that many of the species of parasitic fungi related to the potato-disease fungus, 
Phytophthora infestans, live over winter in the tissues of their host as well 
as in the form of resting spores. This is the case in Phytophthora cactorum 
(in Panax quinquefolium) , Cystopus candidus (in Capsella and Lepidium), Plasmo- 
para viticola (in the vine), P. pygmaea (in Hepatica acutiloba), P. Halstedii (in 
Helianthus diversicatus), Peronospora Dipsaci (in Dipsacus Fullonum), P. Schachtii 
(in beet), P. alsinearum (in chickweed), P. grisea (in Veronica hederaefolia), 
P. effusa (in spinach and orach), P. Ficariae (in Ranunculus Ficaria and R. 
fascicularis) , P. parasitica (in cress), P. Viciae (in Vicia sepium), and P. rumicis 
(in sorrel). The presence of living mycelium of Phytophthora infestans in the 
potato tuber is therefore by no means a unique phenomenon among its allies. 
F. J. C. 
Pine, Canker of the Scots, caused by Dasyscypha subtilissima, Cooke. By 
A. W. Borthwick, D.Sc, and Malcolm Wilson, D.Sc, F.L.S. (Trans. Roy. Scot. 
Arbor. Soc. xxix. pt. 2, pp. 184-187 ; 1915)- — During recent years several 
accounts have been given of the occurrence of the larch canker on various 
species of Pinus. Hopkinson has recorded its occurrence on Pinus Laricio, 
and points out that it may also be found on P. sylvestris and P. austriaca. 
Massee has also recorded its occurrence on the Scots and Austrian pines as well 
as on the silver fir. 
Our present knowledge goes to show that the fungus is not of infrequent 
occurrence on the above-mentioned species. It must, however, be borne in 
mind that Dasyscypha Wilkommii is not by any means the only species of 
the genus which produces canker on these trees, and it is possible that some con- 
fusion has arisen owing to the great resemblance which exists between the 
fructifications of the several species which cause disease in conifers, — A . D. W. 
Pine Shoot Moth, The European. A Serious Menace to Pine Timber in America. 
By August Busck ( U.S. A . Dep. Agr., Bur. Entom., Bull. 170, Feb, 1915 ; 6 plates) . — 
This moth, known scientifically as Evetria buoliana Schiffermiller, has been 
recently introduced from Europe on imported pine seedlings and has become 
established in widely-separated localities in the Western and middle States, Its 
attacks are confined to all species of pine ; it does not touch any other conifer. 
