22 KANSAS UNIVERSITY SCIENCE BULLETIN. 



self-fertilization and cross-fertilization between flowers of the 

 opposite type opening simultaneously on the same raceme are 

 possible. ,; 



The writers have not made sufficiently extensive observations 

 to arrive at any general conclusions of value as to the compara- 

 tive fertility of cross- and self-pollination, either between flowers 

 on the same or different racemes, or between the flowers of dif- 

 ferent plants, but they have been able to obtain a limited series 

 of definite results which may be of interest. 



In making experiments to determine these points, all old 

 flowers were removed from the plants in the afternoon or even- 

 ing and the plants covered with a small ''tent" of cheese-cloth. 

 The cheese-cloth was of a mesh sufficiently small to prevent the 

 access of any insects large enough to effect pollination, while 

 large enough to allow a ready circulation of air and good il- 

 lumination. The following morning pollination was effected 

 between the flowers which had opened by tapping pollen from 

 the large anther onto a clean glass slip and transferring it to 

 the stigma of the same or another flower. The plant was then 

 again covered and allowed to remain so, except when examined 

 from time to time, until the corolla and pistil had fallen off. 

 The following results were obtained from three plants upon 

 which observations were made : 



Plant I. 



August 20. (a) Twelve stigmas pollinated with pollen from 

 large stamen of the same flower, (b) Cross-pollination effected 

 between two flowers which had opened on a raceme at the same 

 time. 



August 22. (a) Five of the twelve flowers had fallen off. 

 (h) One flower had fallen off. The other seemed to be develop- 

 ing. 



August 24. (a) Five ovaries with their corollas fallen off ap- 

 peared fresh and healthy and seemed to be developing. Two 

 more of the twelve had dropped off. (M Remaining pod seemed 

 to be thriving. 



6. Experiments for the determination of the fertility of close and cross-fertilization are 

 always interesting, but are of especial interest in the case of a plant such as .v. rostratum, in 

 which, if the method of pollination described by Professor Todd is the one actually depended 

 upon, cross-pollination is sometimes possible and sometimes impossible on the same raceme. 

 Of course, if, as suggsted in the latter portion of this paper, the method of pollination sug- 

 gested by Professor Todd is not the only one, these experiments do.not have the interest which 

 they otherwise would. 



