134 
BOTANY: A. B. STOUT 
in cell lineage uncontaminated by the recombinations involved in the reduc- 
tion and fusion accompanying sexual reproduction. The evidence is hence 
very conclusive that the hereditary complex and that individual units of the 
complex are subject to variations that become manifest either as sudden muta- 
tions or as fluctuating variations, and that any of these may perpetuate 
themselves. 
The facts suggest strongly that the possibilities for the development of red, 
green and yellow may be present in all cells as metidentical characters (in the 
sense used by Detto, 1907). The total production, the distribution, and the 
concentration of the various chemical substances concerned, however, plainly 
involve interactions between different cells or groups of cells and are in this 
sense epigenetic. The explanation suggested by the production of patterns 
in colloids by the Liesegang precipitation phenomena, especially as applied by 
Gebhardt (1912) to the markings of butterfly wings and by Kuster (1912, 
1917) to the development of many types of variegation in plants including 
Coleus, seems to apply to the production of color patterns in Coleus. On this 
view colored patterns may be considered as due to the formation of localized 
centers for the development, diffusion and concentration of pigments. 
In Coleus both the (1) fundamental quahties (metidentical) and the (2) proc- 
esses of cellular and tissue interaction immediately involved in the develop- 
ment of patterns exhibit spontaneous changes that are continuous in degree 
and are quite constant from the first or can be made so by selection. 
Colored illustrations of the principal color patterns obtained, together with 
the presentation of data (for the first four years of the study) have already 
been presented (Stout 1915). With the facts and conclusions there given, the 
results since obtained are fully in agreement. 
Baur, E., Zs. Ind. Abs. Vererbs., 1, 1909, (330-351). 
Castle, W. E., and Phillips, J. C, Piebald rats and selection, 1914. 
Cramer, P. J. S., Kritische Uebersicht der bekannten Falle von Knospenvariation, 1907. 
Detto, C, Biol. Centralb., 27, 1907, (80-95, 106-112, 142-160, 162-173). 
Gebhardt, F. A. M. W., Verh. Deuts. Zool. Ges., 22, 1912, (179-204). 
Jennings, H. S., Genetics, 1, 1916, (407-534) ; ^wer. Nat., Lancaster, 51, 1917, (301-306). 
Kuster, E., Beitrdge zur entwicklungs mechanischen Anatomic der Pflanzen, 1913; Flora, 
10, 1917, (1-33). 
Shamel, A. D., Scott, L. B., and Pomeroy, C. S., Washington U. S. Dept. Agric. BuU.y 
1918, Nos. 623, 624, 697. 
Stout, A. B., Bull. Torrey Bot. Club, 40, 1913, (367-372); Carnegie Inst., Washington, 
1915, Ptib. No. 218. 
de Vries, H., Die Mutationstheorie, 1901. 
Winkler, H., Ber. Deuts. Bot. Ges., 25, 1907, (568-576). 
