DISEASES OF PLANTS. 431 



plowing- with a scooter plow at intervals of 1 to 3 weeks; and (4) by 

 growing- a crop of oats followed by a crop of cow])eas planted in drills 

 2A ft. apart and cultivated twice. 



On the germination of oily seeds, LecleRc di'Soolon {Compi. Fiend.. 119 {1894), 

 Xo.l',, pp. 010-G12). 



Photographing of seed and an apparatus designed for tliat purpose {Eder's 

 Jahrh. Phot. u. lleproductiontechnik, 1893, pp.5; ahs. in Bot. Centbl., 60 {1894), No. 7, p. 

 202). 



The Russian thistle in Illinois, G. E. Morrow {lUinois Sta. Jiiil. ,97, pp. 4, 

 ph. 2). — A x>opular bulletin giving information regarding the Russit'utbistlo {Salsola 

 kali iragus). It has been reported from 9 stations in the State, and its presence can 

 be ratlier easily trac(ul to the northwestern region, where it abounds. 



Cyperus rotundus, J. II. Hart {Hon. ^ot. Gard. Trinidad Misc. Bui. ,24, p. 303). — 

 The author briefly describes the presence of this pernicious weed and recommends 

 the thorough working over of tlie ground and picking out the roots every 7 or 8 days. 

 It is comniouly known in Trinidad as devil grass, or coco-chatte. 



The destruction of weeds, Wittmack {Fiihlinri's landtv. Ztq., 43 {1894), Xo. 9. pp. 

 59.^-591). 



"Weeds of Ontario, .1. H. Panton {Ontario Agl. College and Exptl. Farm Rpt. 1893, 

 pp. -27-31, figs. 4).— A reprint from Bulletin 91 (E. S. R., 5, p. 529). 



DISEASES OF PLANTS. 



Crown knot, J. W. Toi'MEY {Ari.zo7ia Sta. Bui. 1, 3d ser., pp. 11).— 

 The author gi^es a preliminary report of observations on the crown 

 knot of fruit trees and vines. Although affecting almost all deciduous 

 fruits, it has thus far been most destructive to the peach. This disease 

 has already been described in California Bulletin 90 (E. S. R., 4, p, 

 503). The author found white ants [Tcrmes fiavipes) nearly always 

 present in the knots, hastening the destruction of the tree. As yet no 

 definite cause is known for the disease, but it is thought that the tend- 

 ency of some orchardists to irrigate too frequently and too much, and 

 to endeavor to make irrigation take the place of cultivation may intiu- 

 euce their formation, as orchards under proper irvigation and cultiva- 

 tion are usually free from the disease, while others growing by their 

 side, but improperly tended, are badly diseased. 



Care in selecting young trees, digging up and burning all badly 

 affected ones, pruning away the knots, and treating the wounds with 

 some antiseptic in the case of slightly affected ones, are the remedies 

 recommended. 



Pear and apple blight, J. Craig {Canada Exptl. Farms Rpt. 189S, 

 pp. 88-95). — A historical statement is given of the discovery and spread 

 in America of the disease variously known as apple blight, pear blight, 

 fire blight, and twig blight. Various authors are quoted on the cause 

 and means for spreading this disease. 



Compiled information is tabulated showing the spread and extent of 

 the disease throughout the Dominion. The date of appearance, char- 

 acter of the injury, varieties affected, and eff"ect of cultivation are 

 given. Of the replies received to the author's inquiry, 44 per cent 



