stout: pollinations in cichorium intybus 441 



3. Differentiation between the male sex organs. 



a. In different flowers; from complete absence through 



various grades of development and function. 



b. In a single flower giving heterodelphy of stamens; 



purely morphological (?), as in species of Labiatae, 

 Cruciferae, and Scrophulariaceae; both morphologi- 

 cal and physiological, as in Lythrum Salicaria; 

 possibly cases purely physiological. 



4. Differentiation between the female sex organs. 



a. In different flowers; from complete absence through 



various grades of development and function. 



b. In a single flower; no marked cases in evidence. 



5. Differentiation within a reproductive organ, among the 



spores and gametophytes developed by or from any one 

 sex organ; morphological or functional or both as a 

 result of {a) sporadic variation, {b) of the intricate proc- 

 esses of reduction division, or (c) from other unknown 

 causes. 



II. Differentiation between individuals as wholes. 



1. In the degree of maleness or femaleness; in which entire 



plants differ in the total differentiation in one or more 

 lines indicated under I; seen in dioecism, polygamo- 

 dioecism, various grades of monoecism and intersexes 

 such as Goldschmidt has described in moths. 



2. In respect to male sex organs alone; giving various grades 



of development from presence to absence, or giving 

 distinct types of stamens for different plants as in 

 Primula, Lythrum, etc. 



3. In respect to female sex organs; parallel with 2 above. 



4. In respect to the particular combination of the various 



types of sex organs; (more involved and of different 



grade than i above), giving different plants with quite 



different types of perfect or imperfect flowers as also in 



Lythrum. 



(In I, 2, 3, and 4 above, morphological differentiations are 



strongly in evidence ; physiological correlations clearly in evidence 



in certain cases; purely physiological differentiations suggested by 



such cases as Cichorium.) 



III. Differentiation between groups of individuals. 



