396 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



grammoidea lutea (indigenous to S. Africa) ; lays its eggs in the moth's eggs, which 

 fail to hatch, and as many as four chalcids emerge from one moth's egg. 



The larva's enemies are Ichneumon spp. and the Argentine ant. 



The remaining pp. 25-48 are devoted to tables explained and referred to 

 in the text. — G. F. W . 



Collybi3 — A Wild Winter Mushroom. By F. C. Stewart (U.S.A. Exp. Stn. 

 New York, Bull. 448, Feb. 191 8, pp. 78-98 ; 10 plates). — This bulletin describes 

 a common wild mushroom, which is excellent as food. The fungus grows in 

 dense clusters on stumps, logs, and buried wood, usually from October to April. 

 It has a reddish-yellow cap, white gills, and velvety-brown stem. Owing to the 

 fact that it grows in cold weather when other flesh}* fungi are scarce, there is 

 little danger of confusing this Collybia -with poisonous species. It is claimed 

 that its flavour and consistency are excellent. Directions are given for cooking 

 and preserving this mushroom.— y4 . B. 



Columnea vedrariensis. By S. Mottet (Rev. Hort. vol. xc. pp. 168-170; 

 1 fig., 1 col. plate). — Columnea vedrariensis is a hybrid of C. Schiedeana and 

 C. magnifica, surpassing the latter in vigour and shape and the former in the 

 brilliance of its flowers. Its scarlet flowers marked with yellow last from March 

 to May.— 5. E. W. 



Conifer Seedlings, Diseases of. By C. Hartley, T. C. Merrill, and A. S. Rhoads 

 (Jour. Agr. Res. xv. No. 10, Dec. 1918 ; pp. 521-558). — Damping-off is 

 the most serious disease of young seedlings, and this may be due to Corticium 

 vagum, Pythium Debaryanum, various species of Fusarium, Trichoderma spp. 

 and Botrytis cinerea. Apart from Pythium, Corticium appears to be the most 

 dangerous fungus for conifers, because these organisms frequently set up the 

 disease before the seed has penetrated the surface. The following fungi do not 

 cause damping-off of seedlings : Aspergillus sp., Penicillium sp., Trichothecium 

 roseum, Fusarium acuminatum, Phoma betae, Choetomium sp., Rosellinia sp. 



Excessive heat or drought will cause injury closely resembling that of damping- 

 off.— A. B. 



Conifers at Leonardslee. By Sir E. G. Loder (Gard. Chron. May 10, 17, and 



24; pp. 225, 236-7, 249-50). — A most valuable and carefully compiled list, giving 

 synonyms, authorities, habitat, and varieties of Conifers in this rich collection. 



E. A. B. 



Cronartium ribieola: Its Morphology and Cytology. By R. H. Colley (U.S.A. 

 Jour. Agr. Res. xv. No. 12, Dec. 1918 ; pp. 618-660 ; 12 plates). — The 

 author finds that the mycelium of this fungus is more abundant in Pinus Strobus 

 than in Ribes sp. In the first, the hyphae cause the cells of the cortex and 

 phloem to separate and form a swelling upon the bark. This is absent in the 

 Ribes. Haustoria may penetrate every cell in the infected part of Pinus Strobus, 

 and they have the characteristic form of C. ribieola. Usually a sheath is formed 

 round each haustorium as it matures. The haustoria on the Ribes are without 

 sheaths and are much smaller. 



The destructive effect on the pine of this fungus varies considerably. In 

 young trees the attack causes their death ; in older trees it causes the decay of 

 wood, and therefore allows other fungi and insects to obtain a footing. 



A full bibliography is appended. — A. B. 



Cucumber Leaf-Spot: Its Dissemination and Control. By E. Carsner (Jour. 

 Agr. Res. xv. Oct. 1918, No. 3 ; pp. 201-220 ; 4 plates). — Angular leaf-spot 

 disease of the cucumber was first noted in Wisconsin in 1914, and its bacterial 

 nature proved in 1915 by Smith and Bryan. The disease is widespread. The 

 infection takes place through the stomata, and occurs chiefly during the day- 

 time. The bacterium B. lachrymans is sensitive to desiccation, and is readily 

 killed by dilute solutions of formaldehyde, copper sulphate, or mercuric 

 chloride. 



No marked variation in resistance or susceptibility has been found between 

 the various varieties of cucumber ; no other genus being attacked by the 

 organism. Spraying checks the disease, but it is of doubtful value as a general 

 commercial practice in combating this disease. Seed treatment offers the 

 greater hope of satisfactory control. — A. B. 



Cucurbita Anthracnose. By M. W. Gardner (U.S.A. Dep. Agr., Bur. PI. 

 Ind., Bull. 727, Dec. 1918, pp. 1-68 ; 8 plates). — The anthracnose of Cucurbita 

 is caused by the organism (Colletotrickum lagenarium (Pass.) Ell. and Hals.), and 



