From JOURNAL OF GENETICS, Vou. 1x. No. 2, January, 1920.] 
[All Rights reserved] 
FURTHER EXPERIMENTAL STUDIES ON SELF- 
INCOMPATIBILITY IN HERMAPHRODITE 
PLANTS. 
By A. B. STOUT. 
(With Plates III and IV.) 
CONTENTS. 
2 PAGE 
Statement of the problem and its relation to the old familiar sex questions 85 
Review of the more recent literature . ‘ ¥ : “ ‘ ‘ 87 
Presentation of new data . ‘ : z : F : ; : 93 
I. Relation of vegetative vigour and maturity to variations in self- 
fertility and self-sterility . . ‘ ° . . : . 93 
1. In Verbascum phoeniceum . : : : ‘ ° 94 
2. In Eschscholtzia californica . ‘ A ‘ ‘ ‘ 96 
3. In Nicotiana Forgetiana Hyb. Hort. . ‘ ‘ > 300 
4. In Brassica pekinensis ES : ; A ‘ 08 
5. In Raphanus sativus. . 104 
6. In Lythrum Salicaria . : : ; s : eas |, | 
7. In Linum grandiflorum. : . : . 105 
8. In Cichorium Intybus . ‘ ‘ A ‘ : - 105 
II. Evidence that self-incompatibility may lead to certain cases of 
embryo abortion ‘ = : ‘ . hes ; ee LOT 
Ill. The heredity of self-compatibility in self-fertilized lines of descent 
in the variety red-leaved Treviso of Cichorium Intybus  . eee i 
1, The J, generation. : ‘ : ‘ 3 eee 
9.. Thed; pesuratiaie ee ee et 
IV. Vegetative vigour and impotence in self-fertilized lines in the 
variety red-leaved Trevisoof Cichorium Intybus 5 ‘ go $6 
117 
1. A degenerate line of descent = ‘ : ‘ 
2. Families of marked vegetative vigour . . ° “ao 
* . * . 120 . 
Discussion and Conclusion . . + - . 
EXPERIMENTAL studies of the compatible and the incompatible - 
relations of the sex organs (including germ cells) in the fertilization of 
hermaphrodites continue to yield evidence that these relations are 
highly fluctuating in. the progeny of a single cross- or self-fertilized 
Journ. of Gen. rx 6 
