F. J. F. SHAW 129 



standpoint, and received a good deal of attention from Chatin.* The work 

 of Fraysse^ deals with the biology of some phanerogamic parasites, but species 

 of Orobanche were not among the number investigated. 



Throughout this paper the names of 0. indica Ham. and 0. cernua Loeffl. 

 have been Used in the sense in which they are used by Hooker. Beck von 

 Mannagetta states that 0. indica Ham. is synonymous with 0. cegyptiaca Pers. 

 and gives this species and the nearly related 0. Muteli Schltz. as being parasitic 

 upon species of Bmssica, and 0. Muteli Schltz. and 0. ramosa L., another 

 related species of the section Trionyclion, together with 0. cernna Looffl. are 

 said to be parasitic upon Nicotiana tabacum. It appears therefore that Beck 

 von Mannagetta's observations of the parasitism of Orobanche on Brassica 

 and Nicotiana agree with the facts recorded by Hooker and described in this 

 paper. In a more recent communication^ the species of Orobanche which 

 are parasitic upon tobacco are given as follows : — 



0. ramosa L. 



0. Muteli Schltz. 



0. cernua Loeffl, and 0. cumana Wallr., a sub-species of 0. cernua. 



0. ludoviciana Nutt. 



The first two species occur also on hemp, tomato, and Brassica and the 

 last species is restricted to North America. 



Koch states that heavy applications of manure lessen the incidence of 

 0. ramosa upon tobacco for a time but that ultimately the crop becomes 

 diseased and succeeding crops show on the whole a more severe infection. 

 More recently Peters and Schwartz^ conducted experiments \^'ith a variety 

 of chemical substances (copper sulphate, sodium chloride, etc.) without 

 obtaining results which enabled them to recommend applications of these 

 substances against Orobanche in tobacco. 



^ Chatin, A., Anatomie comparee des vegetaux jdantes parasites, Paris, 1892. 



2 Fraysse, A. Contribution a la biologie des plantes Phanerogames parasites, Mont- 

 pellier, 1906. 



3 Peters, L. and Schwartz, M., " Krankheiten und Beschadigimgen des Tabaks." Mitt. 

 Kais. Biol. Anstalt f. Land u. Forstwirtschnft Heft 13, Berlin, 1912. 



* Peters and Schwartz, lac cit. 



