DISEASES OF PLA^'TS. 989 



Seed testing, T. Diktkicii {Jahrefihcr. lanilw. I'ers. Stut. Marhiirij, 1SD'>-9G, pp. 

 7-9). — A brief report is givin of tlie work done dnrintj the year in testing various 

 kinds of seed. Those most fretiuently received for testinj; were red clover, Swedish 

 clover, alfiilfii, ;md licet seed. 



Reserve store of seeds, E. Convkeiii {Ann. Sov. I.hm. Li/on, 22 (1S9I!), pp. 145- 

 148; ahs. in Jour. Ron. Mwros. Soc.,lS97, ll,p. 1,>5). — The reserve storesof starch and 

 oil in Ricinus ronnnnHis are said to increa.se proportionately in the seed whether 

 attached to the plant or not. During germination tlie starch disapi)ears rapidly, 

 th(i oil more slowly. 



Influence of electricity on germination, G. Tolomki {Malpiglria, 10 (ISQi:), pp. 

 49,3-511, Ji (J s. .?; alis. in Jonr. L'oji. Micron. Soc, 1S97, II. p. 142). — The anthor thinks 

 that currents of great frequency have an injurious effect upon the vitality and con- 

 sequently on the gerniitiation of seed and that the intensity of the injury varies 

 with the species. 



On the structure of the seed coats of some Euphorbias, P>. (iUAM (Hot. TitLsskr., 

 20 [ISriG), So. 2, pp. ■15S-.;89. pis. 5). 



Cutting and mounting sections of cereal grains and starchy tubers, J. D. 

 Hv.\TT (Ji>nr. X. y. .^[i(■ros. Soc, IS (1S97), Xo. .',pp. 19-. '4, pi. 1). 



On the presence and localization of hydrocyanic acid in seeds of certain 

 Pomaceae, L. Liiz (Ilnl. Soc. Hot. France, 44 (1897), Xo. 1, pp. 2G-32). 



The ^vorst ■weeds of "Wyoming, A. Nelson ( Wyominfi Sta. lipt. 1896, Appen., pp. 

 267-S20, Jigs, i.7).— A reprint of Bulletin 31 of the station (E. S. R., 8, p. 794). 



DISEASES OF PLANTS. 



Sunstroke of the vine, F. T. Bioletti ( California Sia. Bpt. Vitieidt. 



Work. 18s7-'93,pp. 4.50, 4.51, pi.l). — IS'otes are given on a diseased condi- 

 tion of grapevines wliicli is characterized as follows: 



"The leaves gradually, or sometimes rajiiilly, dried up and fell off, leaving the 

 shoots exposed and allowing thorn to be killed by the sun. The vines first showed 

 effects of the trouble in the early part of the summer, and some of those first 

 attacked, thougii losing all their leaves, partly recovered and sent out new leaves. 

 The leaves when first attackeil often became spotted in a way somewhat resembling 

 the Anah<'iui disease, but with the important difference that the line between tlie 

 healthy tissue and the dead was clearly marked with little or no diseased tissue 

 between." 



Specimens of leaves and fruit were examined and no fungus par- 

 asites were found. It is thought to be the same as a disease known in 

 France a,»folleta{/c, whicdi is physiological and not pathological in its 

 character. It is caused by anything which disturbs the e(iuilibrium 

 between the water evaporated from the leaves and that taken up in the 

 roots. A sudden period of dry hot weather or a sudden rise or fall of 

 tlie water level may jiroduce it. It is believed that there is no cure if 

 the vine is badly affected. Conse(iueiitly it is important to avoid the 

 cau.ses which produce the disease by careful management of irrigation 

 ai'd close attention t<t water level. 



Investigations of plant diseases in the forcing house and gar- 

 den, A. \). HeliJv {Ohio iStd. Jhil. ;.;, pp. .2:J}--J4li, pis. •/,.AV/.s'. .').— A 

 preliminary report is given upon investigations of diseases of lettuce, 



