46 



blossom is an olon^ation of the axis l)ot\veeu calyx and corolla (Fl.i;;. ')h'). 

 At lirst si.i,iit it ini.uJit a])i)ear that the presence of the parasite was suffi- 

 cient to change the sex of the plaiif, tor tlio fungus, when present in the 

 pistilhite plant, leads regularly 1<i the development of stamens and the 

 suppression of the pistil. However, in this case the capacity to develop 

 stamens must be assumed to be present in the pistillate plant, and the 

 parasite is able to induce the conditions necessary to their formation and 

 the suppression of the pistil, and thus provide for the development of its 

 own. spores. Extensive and elal)orate experiments by Strasburger upon 

 uninfected plants with the view of duplicating the effects produced by the 

 parasite, led to no definite results. 



Pig. 3. Staminate and pistillate riowers of Lychnis dioica L., halved longitudinally. 

 (I. normal staminate Hower. b. normal pistillate Hower. a' staininate flower affected 

 by the smut, Ustilago violaceae; the anthers contain smut spores instead of pollen. 

 b' pistillate rtower similarly affected: the pistil lias remained rudimentary while anthers 

 have been developed, which, however, bear only smut spores. The presence of the 

 parasite has induced the development of anthers, the members of the Hower bearing 

 male spores instead of the parts bearing the female spores,— After Strasburger. 



