BY THE SELECTION OF SOMATIC VARIATIONS. 75 



feature of this variation is the marked tendency to the production of 

 laciniate leaves during winter or after a period of particular drought 

 during summer. 



(8) The behavior of the laciniate character was observed in three 

 subclones (see table 4) of 4, 2, and 2 generations, totaling 68 plants. 

 In 67 of these plants the laciniate type of leaf appeared as a definite 

 character, with a marked tendency to a periodic summer and winter 

 fluctuation, 



(9) Plants with the laciniate leaf character also showed wide fluctu- 

 ations in regard to the degree of green or yellow coloration. When 

 grown for a period of a year from cuttings made in autumn, the leaves 

 were as a rule entire and slightly yellov/ in autumn, deeply laciniate 

 and pure green in winter, and entire and very yellow during the 

 following summer. 



(10) In sexual reproduction all the principal types of variegation and 

 leaf-shape appear at once in an Fi generation, with also numerous 

 types that were intermediate and fluctuating. The extremes of vari- 

 ation are no greater than those obtained in vegetative propagation, 

 although some new types of entire leaves were thus obtained. 



(11) Between any two types numerous intermediates arose, showing 

 that we have here no evidence of the somatic segregation of invariable 

 pattern factors. 



(12) In the bud variations, decrease of red occurred with about twice 

 the frequency as did increase of red; likewise decrease of yellow 

 occurred about twice as often as the increase of yellow, indicating a 

 definite tendency for variations in the direction of the increase of green 

 and the decrease of red. These facts are doubtless due to fundamental 

 relations between the chemical compounds involved. 



(13) The types of color changes involving (a) green and yellow and 

 (6) red and non-red occurred entirely independently of each other. 



(14) The types produced by bud variations are the equivalents of 

 the "Kleinarten" or the ''biotypes" commonly occurring in cultivated 

 species propagated by seed. 



(15) Selection within clones is effective in securing progenies of new 

 types with as high degrees of constancy as is possessed by ordinary 

 cultivated races. 



(16) The results indicate that slight variations arising either as 

 sudden mutations or as gradual fluctuations can perpetuate themselves. 



(17) The green, yellow, red, and non-red colorations in Coleus can 

 best be characterized as metidentical characters; that is, they are the 

 same in the cells as in the tissue and their appearance is possible in 

 the development of any cell. 



(18) The distribution of the colors giving pattern characters are 

 properties of groups of cells and tissues as such. Pattern characters 

 are probably due entirely to tissue and cellular interactions. 



