318 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



basidmm vitis var. tuberculatum — but now regarded as an Exobasidium, 

 and a stage of the development of Deiuatium pullulans. — M. C. C. 



Grapes, Coulure or Non-setting of. By E. H. Rainford (Qu. 

 Agr. Jour. x. pp. 41-42; 2 plates; January 1902). — Coulure appears 

 under two different forms, one, the failure of the flower to set the fruit 

 in all or part of the cluster ; another, in which the fruit sets and in- 

 creases in size, shortly to fall off the bunch in greater or less quantities, 

 as the attack may be severe or mild. The causes of this serious defect 

 are two, constitutional and accidental. 



Constitutional coulure is attributable either to defective sexual organs 

 of the flower or to degeneration of the plant. The cause of this class 

 of coulure is, apparently, cultivating the vine in badly drained land. 



Accidental coulure is caused by (1) adverse meteorological conditions 

 at flowering time, (2) too great a vigour of vegetation, (3) fungus 

 attacks of the flower and immature berries. 



Fungus attacks may be by anthracnose or oidium. In the latter 

 case treatment with sulphur and lime is recommended. 



In the case of coulure due to abnormal climatic conditions nothing 

 oan be done but to take it as philosophically as possible. — M. C. C. 



Grasses, Ornamental, for Bouquets. By Jules Rudolph (Rev. 

 Hort. pp. 95-97 ; February 16, 1902). — Six woodcuts, with an interesting 

 descriptive list of decorative species suitable for association with flowers 

 in floral arrangement, especially in a dried state, and therefore permanently 

 useful.— C. T. D. 



Gunnera, Contributions to our Knowledge of the Genus. 



By Hans Schnagg (Flora, vol. xc. 1902, pp. 114-160 ; 28 woodcuts). — 

 A very full and conscientious study chiefly of the anatomy of this 

 interesting and isolated genus. The ovule becomes completely adnate to 

 the walls of the ovary, and the micropyle closed by the dovetailing of 

 the cells that bound it when young. The nuclear divisions in the 

 embryo-sac are irregular and multiple after the first four have been 

 formed in the usual order. Two of these nuclei pass to the upper pole, 

 one dividing to form the small synergids, the other simply enlarging to 

 form the oosphere. Several — as many as five are figured — fuse to form 

 the endosperm-nucleus. Endosperm formation is not parietal, but limited 

 to the basal part of the embryo-sac, and possibly the antipodals (6-7) 

 take part in it. The enlargement of the embryo-sac with its contents 

 determines complete absorption of nucellus and integument. The 

 reserves in the endosperm are aleurone-grains, each nearly rilled by 

 a large cubical crystal. Despite the enormous differences of size of the 

 vegetative organs in the several species of the genus there is no general 

 corresponding differences in the absolute size of their histological 

 elements. But G. chilcnsis has much the biggest vessels. — M. H. 



Habenarias, Hardy. By G. R. (Die. Gart. p. 330 ; 12 4, 1902). 



Of this genus of hardy terrestrial Orchids twenty species are described 

 and cultural notes given. — G. B. 



