Reproduction 369 



reports it has been stated that very often a definite effect 

 is due to the source of the pollen. An analysis of the data 

 seemed to indicate that the observations which have been 

 made neither positively confirm nor deny a direct and 

 specific stimulation of the pollen upon the fruit-production. 

 In the paper previously referred to, Waite draws this 

 conclusion: There seemed to be, however, constant 

 differences between the Bartlett fruits crossed with dif- 

 ferent kinds of pollen. If these distinctions can be con- 

 firmed by future experiments, a question of considerable 

 importance will be settled/' Lewis and Vincent seem to 

 concur in the belief that there is an immediate effect of 

 the pollen, and they cite the deep red color in Spitzenberg 

 apples pollinated with Arkansas Black as compared with 

 the lighter red obtained when Jonathan is the pollenizer. 



218. Parthenocarpic development. - - It is considered 

 to be a general rule that lack of fertilization is followed by 

 more or less prompt shedding of the infertile blossoms. 

 There are, however, important exceptions to this course of 

 development. Seedless fruits of garden and orchard crops 

 are known. Seedlessness, or imperfect seed development, 

 is very property associated with the failure of fertilization, 

 although it may happen that some ovules fail to develop 

 after fertilization. On the .whole, it seems to be clearly 

 demonstrated that in some cases the ovary and attached 

 parts, technically the fruit, may develop as a purely vege- 

 tative organ, varying more or less, of course, in size from 

 its normal form when fertilization has taken place. 



Among vegetables the cases of parthenocarpic develop- 

 ment best known are those of the English forcing cucumber 

 and certain varieties of the eggplant. Gardeners fre- 



2B 



