EXPERIMENTS WITH BLOSSOMS <»F DATURA TATULA. 19 



EXPERIMENTS WITH BLOSSOMS OF DATURA TATULA. 



The destructive effect of a premature pollination having been found 

 to be so pronounced in the case of tobacco flowers suggested a trial 

 of its effect on a related plant. Some young jimson weeds {Datura 

 tabula) were placed in pots and kept in a greenhouse, where they soon 

 came into flower, hut unfortunately did not bloom profusely enough to 

 furnish similar flowers in sufficient quantity to admit of experiments 

 such as wen' performed with tobacco flowers. The following method 

 was therefore adopted: From day to day these plant- were examined 

 and tiowers in various stages of advancement were operated upon and 

 the records made on labels attached to the plants at the petiole of each 

 flower. As the see<l pods resulting from the labeled flowers ripened 

 or dried up they were cut and a record made of the size of the cap- 

 sule, the number and condition of the seeds, etc. On the completion 

 of the work an examination and classification of these labels showed 

 results similar to those obtained in the case of tobacco flowers, with 

 the one exception that the capsules of the prematurely pollinated 

 flowers did not fall loose from the plants, but hung on for several 

 weeks, although the ovaries did not grow any after pollination and 

 contained no seeds. Pods resulting- from flowers to whose stigmas 

 pollen had been applied at the proper time were of normal size — 1£ 

 inches in diameter— and full of good, plump seeds; while pods from 

 prematurely pollinated flowers were scarcely larger than they were 

 when the flowers were pollinated, usually one-eighth to one-fourth of 

 an inch in diameter, and contained no seeds. The only instances in 

 which good seeds were found in pods from prematurely pollinated 

 flowers were those in which the stigmas had been pollinated when 

 exceedingly young and the flowers not emasculated. In some cases of 

 this kind, and the same is true of tobacco flowers, the very young 

 stigmas overcame the results of the early pollination and the flowers 

 were later self -pollinated and produced seed. Indeed, the work with 

 Datura blossoms indicates fully as strongly as does that with tobacco 

 flowers that there may be a stage a certain time before maturity when 

 the flowers suffer more from premature pollination than they would 

 suffer from an earlier pollination. It may be necessary for the pistils 

 or stigmas to reach a certain stage of development before pollen tubes 

 can penetrate them. 



EXPERIMENTS WITH COTTON BLOSSOMS. 



While hand pollinations were being made in order to obtain hybrids 

 between Sea Island and upland cottons, the question arose as to whether 

 the pollen could be applied at the time of emasculation with as good 

 results as if applied to perfectly mature pistils. If such could be 

 done much labor would be saved. Accordingly the work was arranged 



