POLLIXATIOX AND FERTILIZATION OF 

 FLOWERS.* 



W. M. MUNSON. 



Several years ago the writer undertook the study of some of 

 the problems connected with the pollination of flowers, and 

 some of the results obtained were published in the report of this 

 Station for 1892. Since that time the pressure of other duties 

 has crowded the work out, but it is now thought possible to 

 make a somewhat systematic study of the subject, and the pres- 

 ent paper is designed to touch upon a few of the more salient 

 points and brmg together data for work during the ensuing 

 year, rather than to treat any one subject exhaustively. 



The peculiar situation of the male sexual element at some 

 distance from the female, and the interposition of a mass of 

 tissue through which the former must penetrate, suggest many 

 problems relative to the coming together of these before and 

 after actual coalescense. The first part of these notes will treat 

 of the histological aspect of the case ; the second is a summary 

 of previous work attempted by the writer. 



NOTES ON FERTILIZATION. 



THE PASSAGE OF THE IMALE NUCLEUS FROM POLLEN-GRAIN- 

 TO EMBRYO SAC. 



On tJie Character of the Pollen-Grain: It is unnecessary at 

 this time to consider the size, form and external markings of the 

 pollen of different species. But, in general, a pollen grain con- 

 tains, besides the large asexual vegetative nucleus of the cell, a 

 smaller generative nucleus, and a certain amount of nutritive 

 material — starch, maltose, etc., — together with diastase and 

 invertase necessarv in rendering the latter elements available. 



*The basis of this paper was presented before the Society for tlie Promotion of 

 Agricultural Science at the Boston meeting, 1S9S. 



