452 EXPERIMENT STATION RECOED. t Vol. 38 



harmful products. The absence or inefficiency of tliis barrier results in a con- 

 dition described as a successful parasitism of tjie plant by its own nodule 

 bacteria or by abnormally developed outgrowths from the altered nodular struc- 

 ture itself, which thus behaves as a foreign body or a parasitic organism. 



The results are discussed of the examination of a large number of Arachis 

 and Soja plants, both of which are found to be subject to this trouble when 

 growing under unfavorable conditions. It is thought that this disorder may be 

 somewhat common in leguminous plants. 



Orobanclie ramosa and O. cum,ana parasites of tobacco iu Roumania, I. 

 Gbintescu (Bui. Dir. Gen. Reg. Monopol. Stat. [Roumania], 2 {1914-15), No. 

 3-4, pp. 10-31, pis. 2, figs. 7; 3 (1915-16), Nos. 1-2, pp. 1-28, figs. 7; 3-4, pp. 

 20-23; abs. in Internal. Inst. Agr. [Rome], Internal. Rev. Sei. and Praet. Agr., 

 7 {1916), No. 5, pp. 767, 762; Bol. Tec. Coltiv. Tabacchi [Scafati], 15 {1916), 

 No. 3-6, p. 91).— It is stated that among the numerous enemies of tobacco in 

 Roumania the Orobanchacefe hold first place for both harmfulness and rapidity 

 of spread. The species known in the various localities named are Phelipcea 

 (O. ) ramosa and 0. cum ana,, the last being now reported for the first time as 

 parasitic on tobacco in that country. Descriptions are given of both species, 

 their varieties, origin, distribution, and the control measures employed. 



Other cultivated plants attacked by these species include hemp, potatoes, and 

 pumpkin. 



Dying of young fruit trees, R. Waters {Jour. Agr. [New Zeal.], 12 {1916), 

 No. 2, pp. 112-121, figs. S). — Following up the introductory article on this subject 

 by Cockayne (E. S. R., 35, p. 456), the author states that in the course of the 

 preliminary investigations conducted by himself concerning the mortality among 

 fruit trees, thousands of young trees were found to be affected with apple 

 canker {Nectria ditissima), New Zealand root fungus {Roscllinia radiciperda), 

 dieback (somewhat rarely), or the sour sap condition mentioned in the article 

 referred to. 



No fructifications have yet been found on apple twigs showing dieback. The 

 sour sap condition, said to be by far the most common disorder of young apple 

 trees in the Dominion, is closely associated with fructifications producing red 

 or golden fibrils and closely resembling those of apple bark fungus {Valsa 

 ambiens) ; with fructifications producing black or white fibrils; or with a 

 fungus the stromata of which burst through the bark and give crescent-shaped 

 summer conidia similar to those of apricot coral spot (A'^. cinnabarina) . Much 

 evidence favors the view that sour sap develops almost exclusively on trees pre- 

 viously weakened by mifavorable soil conditions or treatment, forms of which 

 are discussed under the heads of soil prejiaration, soil water, feeble nursery 

 stock, unsuitable varieties, bad planting, lack of shelter, and pruning, with men- 

 tion of other possible causes. 



Dying of young fruit trees, R. Waters {Jour. Agr. [Neio Zeal.], 14 {1917), 

 No. 3, pp. 190-196). — Emphasizing the claim noted above that the main cause 

 of debility resulting in sour sap of fruit trees is the undue accmnulation of 

 water in the low situations in which they are planted and the consequent lack 

 of aeration in the soil, the author outlines the apparent relations of the sour sap 

 condition to the various fungi found in connection therewith. 



This condition in the wood, cambium, and bark of young apple trees is com- 

 monly followed by the appearance of at least six kinds of spore-bearing organ- 

 isms, of which there have been Identified, with more or less probability, Valsa 

 ambiens, V. auerswaldii, Diplodia griffoni, and Fusarium latcritiutn. The most 

 marked results of inoculation which were obtained came from tests with a 

 fungus which has not yet been identified. It appears that the fungi associated 



