DISEASES OF PLANTS. 345 



have fallen. Ahnnf 2 more ai)i)Iicatioiis should Ix' siivcn at intervals of 10 days 

 to 2 weeks, dc'iiendiiii; upon the weather conditions. 



Lathrsea clandestina, a parasite of the vine, A. Col (Coniiit. Rend. Acad. 

 Set. U'aris]. JJ,S {ID09),No.2.i,pi). 1J,15, 1476; Rev. Vit., 31 (1909), No. 807, jip. 

 621, 622). — An account is given of an injury to grapes in Loire-Iuferieure, 

 France, which was found to be due to a phanerogamic parasite (L. clandestina) . 

 Additional studies are being carried on to determine the method of attack and 

 means for control of the iiarasite. 



Carnation root knot, H. Gauman {KcuIhcI-ii tita. Bui. 1^2, pp. 207-216, pis. 

 .'i. Jiffs. J. dffin. 1). — Tlie author's attention was called to a diseased condition of 

 carnations in which the plants were stunted and the roots covered with an 

 extensive development of swellings and knotty growths. An examination of 

 these swellings showed that the plants were infested with nematodes, and the 

 author believes that the species present was that commonly described in Europe 

 under the name Heterodera radicicola. In addition to carnation plants, a large 

 number of other plants in the station conservatory have shown that they are 

 sub.1ect to attack. 



Various methods of treatment are described at some length, and in conclusion 

 the author suggests the destruction of all plants if badly infested, the freezing 

 of the soil during winter, and drying and sterilizing by heat during summer. 

 For outdoor treatment, the jtractice often followed in Europe of planting trap 

 crops is recommended. 



Mycorrhizae on Michigan trees, G. A. Duthie and D. M. Matthews {Rpt. 

 Mich. Acad. ScL, 10 (1908), p. J/6). — An examination was made of 2G species of 

 forest tree roots to determine the presence of mycorrhizje, and 16 were found 

 to be associated with ectotrophic mycorrhizse, 7 with endotrophic, while 3 were 

 apparently free from any fungal affection. The ectotrophic species were the 

 red, white, and black oak, tamarack, Norway pine, chestnut, American elm, 

 m-ockernut and bitternut hickories, beech, blue beech, ironwood, black cherry, 

 trembling aspen, poplar (Popiilus grandidcntata), and paper bark birch {Bctnla 

 jmpyrifera) , wliile the endotrophic species were swamp and sugar maple, bass- 

 wood, horse chestnut, walnut, butternut, and sycamore. Those which showed 

 no mycorrhiza, so far as the authors were able to determine, were black and 

 Avhite ash and willow. A superficial examination of the tulip tree, Ailantlius 

 {/landiilosa, and papaw seemed to indicate that they too were nnaffected. 



Mycorrhiza-producing' Basidiomycetes, L. H. Pennington (Rpt. Midi. Acad, 

 ^ci., 10 (190S), pp. .'i7-50). — A study made of recent literature shows that little 

 investigation has been reported regarding endotrophic mycorrhiza, and a series 

 of studies was carried on to determine the relationship of tlie fungus to mycor- 

 rhiza. A number of species of Basidiomycetes have been reported as producing 

 mycorrhiza upon the roots of trees, and the author's observations have sliowii 

 that Russula enietica, Boletus speciosus, Tricholoma transmutans, and an 

 undetermined species of Cortinariiis produce mycorrhiza on certain species of 

 oaks. It is further reported that B. speciosus produces sclerotia, and it is said 

 that this seems to be the first time that sclerotia have been reported in connec- 

 tion with P><)]('tus and with mycorrhiza. 



Diseases of chestnuts in the United States and Europe, E. Henry (Ann. 

 Sci. Agron., 3. ser., Jf (1909), I', No. J/, pp. 2^1-251). — Descriptions are given of 

 the disease in America caused by Diaporthe parasitica (E. S. R., 19, p. 250) 

 and of the disease in Portugal and elsewhere which is characterized by the 

 blackening of the roots due to a tannic exudate coming in contact with iron 

 salts in the soil. Bacteria and the mycelium of fungi have been found in con- 

 nection with the diseased roots but the exact cause has not yet been positively 

 determined. 



