230 Cornell Extension Bulletin 10 



Modern observation, through experimentation, has established the 

 fact that hybridity does not necessarily mean weakness. On the contrary, 

 in many cases hybrids have attained greater vigor than their parents. 

 The modern gladiolus, with its great size of bloom and vigor, is superior 

 to any species as yet employed in hybridization. Very probably this 

 progress in vigor is due to hybridity and continued selection rather than 

 to the inheritance of any acquired character resulting from modified 

 culture or ecology. Plant breeders in the main have rejected the theory 

 of Lamarck that races are developed by the accimiulation of the effects 

 of use and disuse, because experimental data are lacking to substantiate 

 the contention. Colors do change, often due to a changed environment; 

 but, as Goodrich (191 2) explains, each variety will reproduce its like 

 in its own locality; but seeds of an alpine plant (he has been speaking 

 of a divided dandelion plant, one-half planted in alpine altitudes, the other 

 half upon the lowlands — each has developed new characters) will produce 

 only the lowland form if sown there, and vice versa; the seeds of the low- 

 land form will grow into the alpine form in the mountains. This change 

 is accomplished by the new growing tissues, for the old and already-formed 

 tissues are no longer capable of altering. Once fully differentiated, they 

 are fixed. So we see the organism is moulded by its environment. It is 

 not the developed result which is transmitted; it is not the modification 

 which is inherited, but the capacity for modification in certain directions — 

 the modificability. 



Besides white, which is due to the absence of color pigments, there 

 are three classes of colors in flowers — the plastid, the cell-sap, and the 

 combination colors. Plastid colors are resident in chromoplasts, the colors 

 of which vary from yellow to red (Bailey and Gilbert, 1915) according 

 to the predominance of yellow xanthophyll or orange-red carotin. 



Cell-sap colors are often due to a chemical substance known as antho- 

 cyanin, which is (Bailey and Gilbert, 191 5) 



blue in an alkaline and red in acid reacting cell-sap, and, under certain conditions, 

 also dark red, violet, dark blue, and even blackish blue. . . . The different colors 

 of flowers are due to the var^/ing color of the cell-sap, to the different distribution 

 of the cells containing the colored cell-sap, and also to the combinations of dissolved 

 coloring matter with the yellow, orange, and red chromoplasts and the green chloro- 

 plasts. There is occasionally found in the cell-sap a yellow coloring matter known 

 as xanthein; it is nearly related to xanthophyll, but soluble in water. 



Xanthophyll is the yellow pigment in chloroplasts. To summarize the 

 nature of these colors, Bailey and Gilbert (191 5) write: 



Yellow, cream, and related colors are due to a yellow pigment either associated 

 with green in the chloroplasts or found alone in the chromoplasts, generally the latter. 

 Yellow may sometimes come from the cell-sap. 



Red color may, under certain circumstances, be due to the presence of that pigment 

 in the chromoplasts, but it is ordinarily a cell-sap color. 



Most of the remaining colors, purple, blue, generally red, pink, etc., are due to pig- 

 ments in the cell-sap. 



