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JOURNAL OF THE KOYAL HOR'nCIlL'rURAL SOCIETY. 



walls had been removed, and very little with seed-coats removed ai 

 ordinary temperatures. 



But when carpels were removed (and still better when seed-coats 

 were removed) and the seeds were placed on wet cotton in an ice-chest 

 at 50 to 6° 0., and even at 0° 0., 'for from 73 to 96 days, and then 

 removed to a greenhouse or water-bath at 10° to 12°, a large proportion 

 (from 50 to 80 per cent.) germinated. 



The loss seemed mainly due to injury in the process of removing 

 carpels and seed-coat, which is a difficult matter. No germination 

 was obtained when seeds were kept dry or under water. Ether had no 

 effect. Without oxygen and with hydrogen either none or very few 

 germinated. At temperatures of — 2^ to — 3° 0. there was no germi- 

 nation. The authors consider that it is because water and oxygen do 

 not penetrate to the hypocotyl that germination is delayed under 

 ordinary conditions. — G. F. S. E. 



Hickory Trees, The Dying, Cause and Remedy. By A. D. 



Hopkins (U.S.A. Dep. Agr., Bur Entom., Circ. IM ; Jan. 1911; 

 4 figs.). — Within the last ten years a very large number of hickory 

 trees have died in various parts of the Northern States, from Wis- 

 consin to Vermont, and southward through the Atlantic States to 

 Georgia. The primary cause of death has been found in most cases 

 to be the hickory bark-beetle {Scolytus quadrispinosus). The adult 

 beetles feed at the base of the petioles, causing the leaves to fall 

 prematurely. They bore through the bark and make short vertical 

 galleries where they deposit their eggs, and the larvse hatching 

 from them excavate radiating food burrows which serve to girdle the 

 tree or branch, which causes injury, if not death, to the tree. Several 

 methods of control are suggested by the author, the principal one 

 being to cut off and bum all infested branches so as to destroy the 

 broods before they emerge in May. — V. G. J. 



Hybrid Seed, Increased Yields of Corn from. By G. N. 



Collins {U.S.A. Dep. Agr. Year Booh, pp. 319-328; 1910).— Uniformly 

 favourable results have been obtained from ten independent experiments 

 in crossing sweet corn. The first-generation hybrids have shown them- 

 selves tO' be almost invariably more productive than the parent strains. 

 On the other hand, their progeny do not show the same vigour; there- 

 fore, to obtain the increased yields, it is necessary to renew the crossing 

 of pure strains each year. — G. H. L. 



Impatiens, Polarity of. By A. Urspmng (Beih. Bot. Cent. Bd. 

 28, pp. 307-310). — The author finds that I. Sultani exhibits the same 

 polarity regarding the formation of roots on the stem as has been shown 

 for other species of this genus. In all cases the plant endeavoured to 

 form its roots as near to the base as possible. — G. F. S. E. 



Indian Meal Moth, The, and ** Weevil-cut " Pea-nuts. By 



0. H. Popenoe {U.S.A. Dep. Agr., Bur. Entom., Circ. 142; Sept. 



