40 KANSAS UNIVERSITY SCIENCE BULLETIN. 



stamen and pistil in S. rostratum seems to the writers to be that 

 of support for the visiting insect. 



8. It might seem that the pollen from the small stamens is 

 of much more importance in the process of fertilization than 

 Professor Todd suspected, especially since it seems that there 

 is much more certainty of the pollen from the small stamens 

 reaching the pistil than there is of that from the large stamen. 

 The fact that there is some question as to the fertility of the 

 pollen from the large stamen in all cases, and that in the case 

 of another plant stamens of somewhat similar arrangement 

 seem to have lost entirely their direct reproductive function, 

 would indicate the same. 



9. In a limited number of cases the pollen from the large 

 stamen of a flower seems to be fertile on its own stigma, as 

 well as upon the stigma of a flower opening simultaneously on 

 the opposite side of raceme. 



10. Spontaneous self-pollination seems sometimes to occur. 



11. The percentage of cases in which seeds develop in those 

 flowers in which artificial pollination is effected in the same 

 flower or in two flowers of the same raceme is much smaller 

 than when cross-pollination is effected by insects, reaching, in 

 the case of the somewhat limited experiments of the writers, 

 only as high as 28.5 per cent. Whether this is partially due to 

 the method of applying the pollen or not has not been deter- 

 mined ; whether the seeds produced by these cases of pollina- 

 tion of the same flower or flowers on the same raceme are 

 capable of germination or not has not yet been determined. 

 It might be suggested that the low percentage of cases is due 

 to a lack of fertility in the pollen of the large stamen. 



12. Estimated from the number of seed pods which nor- 

 mally develop, the number of flowers in which pollination is 

 not effected is very small, not reaching, in the observations of 

 the writers, much over six per cent. 



Cassia chamaecrista. 



1. Right- and left-handed flowers are produced at the same 

 time on the plant. When several plants are taken, the number 

 of right- and left-handed flowers produced is practically the 

 same. 



2. So far as observed, two flowers were never seen open at 



