NOTES AND ABSTRACTS, 
207 
that locality. It is usually very peculiar in appearance, having a stem curved 
at the summit and with few short branches, forming a very narrow crown. It 
is common near Cambridge in hedgerows, and has been seen in Lincolnshire, 
Norfolk, Suffolk, Essex, Northampton, Bedford, Oxfordshire, and Hampshire. 
It is closely allied to the Cornish elm, Ulmus stricta, wild in Cornwall, but has 
a different habit and a distinct distribution. See " Trees of Great Britain," 
vol. 7, p, 1 90 1. — A. D. W. 
Violas, Dwarf, for Rockery. Anon. {Irish Gard. xi. p. 81). — Deals with the 
cultivation and use in the rock garden of Viola gracilis, V. arenaria rosea, 
V. bosniaca and some of its forms, V. calcarata, V. cenisia, V. cornuta and the 
var. Papilio, V. cucullata, V. glabella, V. hederacea, V. Munbyana, V. olympica, 
V. pedata (a difficult plant), V. rothomagensis, and V. Rydbergi. V. gracilis and 
its forms, of which ' Golden Fleece,' ' Blue Jay,' and eburnea are good, is apt 
to " flower itself to death," and should be cut over before all the flowers are 
dead to induce it to break out at the base. — F. J. C. 
Water, Hot, against Plant Pests. By Achille Magnieu {Jour. Soc. Nat. 
Hort. Fr. July 1915, p. 104). — An article pointing out the great additional 
emcacity of spraying mixtures, both against insect and fungoid pests, when applied 
hot. The winter has proved by experiment that with vines and fruit-trees 
the fully-grown leaves are not permanently injured by a spraying with liquid at 
75°C, continued for a few seconds. Young immature growth will stand spraying 
in the same way at a temperature of 70°C, and flower-buds, flowers, stamens, &c, 
can bear it up to 65°C. 
The hotter the mixture the greater seems to be its moistening power, and 
one or two sprayings carefully and thoroughly carried out at suitable times will 
serve to destroy both the insects and their eggs. 
For fungus diseases hot solutions are also useful, though of course their 
action is curative, not preventive, and they must not be expected to destroy 
mycelium in the interior tissues. There exists at present no apparatus specially 
designed for applying hot solutions, but they may be quite successfully 
managed with the help of a portable iron copper. — M. L. H. 
Water of the Soil, Studies on the Relation of the Available, to the Hygro- 
scopic Coefficient of the. By F. J. Alway {U.S.A . Exp. Sin., Nebraska, Res. Bull. 3, 
June 1913 ; 122 pp.; 37 ill.; 36 tables). — Contains the results of a four- 
year series of experiments carried out to determine the amount of water 
available to the plant as compared with its total available water and hygro- 
scopic coefficient. 
For these experiments a number of cylinders, 6 feet long, 6 inches diameter, 
were used, holding about 100 lb. of soil. To this soil was added the requisite 
amount of water, and various plants were grown without any further addition of 
water until the plants died. 
The total and free water was then determined, and the distribution of roots 
observed. 
It was shown that the amount of soil water available to plants was approxi- 
mately equal to the free water, viz. the difference between the hygroscopic co- 
efficient and the total water available to and occupied by roots. — C. P. C. 
White-Fly Control, 1914. By J. R. Watson {U.S.A. Exp. Sin. Florida, Bull. 
123, Sept. 1914; 5 figs.). — " The ideal method of controlling the white fly is to 
spread parasitic fungus during the rainy season and to spray with miscible oil 
emulsion in spring and fall." — V. G. J. 
White-Fly, The Woolly. By J . R. Watson {U.S.A. Exp. Stn. Florida, Bull. 126, 
March 191 5; 9 figs.). — The woolly white-fly {Aleurothrixus Howardi Quaintance) 
is rapidly spreading ; it usually does little damage, but is certainly capable of 
causing great harm unless preventive measures are taken. It is heavily 
parasitized by a minute wasp-like fly, which sooner or later controls an out- 
break. Because of this it will probably never develop into as serious a pest 
as the common Citrus white-fly. — V. G. J, 
Windbreaks and Ornamental Planting. By R. W. Allen {U.S.A. Exp. Stn., 
Oregon, Bull. 125, Feb. 191 5 ; figs.). — Gives many hints on the formation of 
windbreaks and on ornamental planting, suggests reasons for the selection 
of certain trees, and advises what to do and what to avoid in the method of 
planting. It condemns the planting of tall-growing trees in such a way as to 
interfere with air drainage. Such barriers to the movement of the air become 
