48 ESTABLISHMENT OF VARIETIES IN COLEUS 



blotched, and green-yellow-solid red, were grown in a greenhouse with 

 northern exposure only, which gave scarcely any direct lighting. These 

 plants were constant for the respective patterns. The green and 

 yellow, however, were slightly less bright and intense. 



During the summer of 1914 several plants of nearly all types of 

 pattern containing yellow were grown in a greenhouse the glass of 

 which was whitewashed to decrease the intensity of illumination. No 

 appreciable differences could be noticed between the patterns of these 

 and of plants grown out of doors. So far as I have observed, it does 

 not seem that any of the color variations can be attributed to such fac- 

 tors as heat or degree of illumination. 



Furthermore, the loss of yellow, loss of green, and gain and loss of 

 red all occurred in single branches and in sections of branches (figs. 

 21 and 24). Frequently two quite different changes appeared on the 

 same plant, which was then grown for some time with 2, 3, or even 

 4 quite distinct types of foliage. Cuttings were made so as to give 

 plants with two types of foliage, as (a) green and green-red blotched, or 

 (6) green-yellow-red blotched and green-red blotched, or (c) green-yellow-red 

 blotched and green-yellow-solid red, etc. In all these cases branches 

 with two types of foliage were submitted to as uniform conditions 

 as possible; they grew on the same plant, were subject to the same 

 degree of heat and illumination, and were supplied by the same root 

 system. Under this test the different patterns were fully as constant 

 as if grown on separate plants. 



These facts indicate quite clearly that the marked and sudden 

 variations and differences in expression of color concerned in the 

 different patterns are not readily attributable to external environ- 

 mental factors. 



Flammarion (1898) used a variety of Coleus with a yellow, green, 

 and red color pattern in testing the influence of light on pigmentation 

 in plants. With red light he secured decrease of red pigmentation 

 and a broader leaf; under influence of green light the red coloration 

 mostly disappeared, and under blue light there was somewhat less red. 

 A series grown out of doors under conditions of diffused light showed 

 decrease of red coloring, while those under very dim light gave still 

 less development of it. With decrease of red the center of the leaves 

 became quite yellow. Evidently the red pigmentation of his variety 

 was chiefly located in the epidermis. In marked contrast to these 

 results it may be noted that the bud variations that I have reported 

 give more marked changes than those induced by Flammarion and 

 that these appear suddenly and in a sector of a bud in a manner that 

 suggests internal readjustments rather than external environmental 

 influence. 



In respect to the laciniate leaf-shape and its periodic development, 

 however, environmental influences seem to have some effect. As 



