PRELIMINARY NOTES ON THE 



SECONDARAY EFFECTS OF 

 POLLINATION. 



By W. M. Munson. 



The change produced by contact of embryo sac and pollen tube 

 is not confined to the mere vivification of one or more cells ; 

 though this is the chief end, — the primary object of all pollination. 

 There are certain secondary effects which are of interest to the 

 botanist and may be of great practical value to the horticulturist. 



When there is a difference between male and female parents, 

 the embryo partakes to a greater or less extent of the nature of 

 both parents. In general, this influence is apparent first in the 

 offspring of the cross ; but in some instances there appears to be 

 an immediate effect on the ovary or other portions of the female 

 parent. In some cases also, the pollen seems to have a direct 

 stimulating influence on the ovarium, without effecting the impreg- 

 nation of the ovules. Again, in certain instances the vigor of the 

 plant seems sufficient to develop a marked growth of the ovary in 

 the entire absence of the male element. The form and size of the 

 ovary are often materially affected by the application of different 

 amounts of pollen to the stigma. In some plants more than one 

 embryo is developed in a single ovule, indicating the possibility of 

 superfostation. These, and other secondary problems arising in 

 connection with the systematic amelioration of cultivated plants, 

 are often of great practical importance. 



The following notes can be regarded only as preliminary ; as 

 forming a basis from which to start in future work in this direc- 

 tion. Although some of the problems considered have been under 

 discussion for more than a century, they are still unsolved. There 

 has not been sufficient systematic study to warrant the formulation 

 of general laws, and this study must necessarily extend over a 

 long series of years. In the notes are embodied as concisely as 

 may be, the more important results obtained by leading experi- 

 menters in this country and in Europe, together with some obser- 

 vations of the writer on the subjects in question. 



Special acknowledgement is due to Professor L. H. Bailey of 

 Cornell University, for the use of certain notes and photographs, 

 and for free access to his private library. 



