FERTILIZATION AND CllOSS-FERTILIZATION. 81 



MEETING FOR DISCUSSION. 



Saturday, February 24, 1877. 



W. C. Strong, Cliairman of the Committee on Publication and 

 Discussion, in the chair. The subject of Self and Cross-Fertilization, 

 as presented by Prof. Goodale, being again assigned for considera- 

 tion, the following outline of the lecture, made by Prof. Goodale, 

 was read b}^ the Secretar}^, that the position of the lecturer might 

 be clearly understood. 



I. By self-fertilization, or close fertilization, is meant the im- 

 pregnation of a pistil by pollen from its own flower. 



Conrad Sprengel, in the last century, and Andrew Knight, early 

 in this century, showed that many flowers are incapable of fertiliza- 

 tion without insect or other foreign aid. 



Mr. Darwin, in England, Mtiller and Hildebrand in Germany, 

 Axtell in Sweden, and Gray in America, have greatly enlarged the 

 list of flowers which require insect aid to ensure their fertilization. 

 These flowers are termed " cross-fertilized." 



II. The mechanism of cross-fertilization may be said to be by 

 1st. vSeparation of the sexes. 



2d. Diflerent dates of maturity of stamens and pistil. 

 3d. Inaccessibility of the stigma, as in orchids, etc. 

 4th. Certain movements which ensure transfer of pollen. 



III. Mr. Darwin, in his recent work on cross-fertilization, estab- 

 lishes the fact experimentally that plants which can be, and are, as a 

 rule, self, or close fertilized, become in a few generations greatly 

 impaired in vigor, as contrasted with the same species cross-fer- 

 tilized, and unequal to contend with them in the struggle for life. 



IV. Many disputants of late have asserted with reason, that a 

 good many plants can be self-fertilized. This is not denied by any 

 scientific man of any repute. What is claimed, and what is in per- 

 fect consonance with such statements is this ; namely, most plants 

 can be in some way cross-fertilized, and this cross-fertilization, even 

 in those species which can he close fertilized^ ensures greater vigor in 

 the progeny. 



It must be noticed that in some recent publications bearing upon 

 close fertilization, the fact that experiments covering many years 

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