568 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
fluctuation of price, and is likely to suffer from over-production if the acreage is 
too rapidlv extended. The cost of establishing the crop and the annual expenses 
of cultivation are high.— M. L. H. 
Perennials Attacked by Ssbrotinia RoKsii. By Geo. L. Peltier {U.S.A. Exp. 
Stn. Illinois, Cir. 187, July 1916). — In the summer of 1915 large numbers of 
perennials were found to be attacked by a fungus, Sclerotinia Rolfsii (Sacc), 
which hitherto was confined to the more Southern States. Usually the first 
indication of the disease is a yellowing and drooping of the leaves of the attacked 
plant. The fungus attacks the plant on the stem just above the ground and soon 
spreads to the roots, finally causing a soft rot of all the parts underground. 
Sclerotia are soon developed and resemble mustard or radish seed in appearance. 
Amongst the perennials attacked were the following : Campanula Medium, 
C. pevsicifolia, C. carpatica, C. nobilis, Erigeron glabellus, Dianthus plumarius, 
Dracocephalum argunense, Pentstemon pubescens, P. Murrayanus, Phlox subulata, 
and Eupatorium ageratoides. Of these the Campanulas were the most susceptible, 
especially C. Medium. — A. B. 
Persimmon, The Native. By W. F. Fletcher (U.S.A. Dep. Agr., Farm. Bull. 
685, Oct. 12, 1915; pi.). — The Persimmon is indigenous in the S.E. quarter of 
the United States ; and the presence of single specimens in Rhode Island and 
Michigan show that the northern limit of its cultivation could quite well be 
extended. 
The high food value of the fruit is not sufficiently appreciated. Masses of the 
crop go to waste for want of knowing how it may be used. Attempts to improve 
upon existing varieties by cross-breeding have also not been completely successful 
because one essential factor has been overlooked. 
The Persimmon is generally dioecious, the pollen being distributed by bees and 
by the wind. In attempting to improve upon native varieties by crossing, the 
characteristics of the pollen-bearing parent should be also studied, and such parent 
should be selected among trees grown from seed produced by the most desirable 
fruit- bearing trees. 
Various methods of cultivation and of propagating are here described, and 
the few diseases of the Persimmon are described. The wood is used for bobbins 
in cotton-mills, and the fruit is a valuable food for man and beast. Its intense 
astringency disappears when the fruit is fully ripe, but, as heat appears to make 
this astringency more apparent, an antidote in the form of half a teaspoonful 
of carbonate of soda should be added when the fruit is cooked. Recipes are 
given, and descriptions of some of the better-known varieties. — M. L, H, 
Picea bicolor. By Professor Henry {Irish Gard. xiii., Feb. 1918, pp. 17-18; 
2 figs.).— E. T. E t 
Pine Bark Beetle. By W. A. Clemens {U.S.A. Exp. Stn., Cornell, October 
1 916). — The genus was formerly known as Tomicus, but the synonymy according 
to Swaine (page 77 of reference cited) gives the name Ips De Geer (1775) priority. 
The species was described by Say (1827). 
It is common and widely distributed, inhabitingthe transitional and Canadian 
faunal zones from the Pacific to the Atlantic and from about 37° to 55 0 Is'. 
Removal of the bark will cause the death of all larvae and pupae of the pine 
bark beetle. If a little care is taken in the lemoval and the bark is burned 
immediately, a large number of the adults may also be destroyed. Reiroval 
and burning of the bark in winter where adults are known to be in hibernation 
will do much to lessen attacks in the season following. Where -water is available 
the placing of newly felled iogs in the water will prevent injury by the beetles. 
A.D.W. 
Pisum sativum, Bacterial Disease of. By Dorothy M. Cayley (Jour. Agr. 
Sci. vol. viii. part 4 Dec. 191 7, pp. 461-479 ; pi. 7). — This is a report of further 
investigations oi a bacterium for which the author proposes the name Pseudo- 
monas seminum* The organism is a motile, sponng, facultatively anaerobic 
bacillus, capable of growth on acid, neutrai, and alkaline media. It is found in 
large numbers in the tissues of the cotyledons of the Pea. A discoloured patch 
in the centre of the colyiedons is typical, but it is not possible to teli from the 
exterior ot the seed whether it :s or is not infected. From the cotyledons the 
infection spreads to the tissues of the stem and leaves. In mild cases the shoot 
may develop normally, but *ater the stem turns slightly brown and looks some- 
what water-soaked. In bad cases either the seed does not germinate or the 
plumule and rad.cle show brown streaks and growth is limited. The organism 
can penetrate uninjured tissues ;rom the outside only when they are very young. 
