The Periodicity of Semi-Latent Characters. 325 



the doubling was seen to increase in intensity in the same 

 way. 



Braun, in his great work on the rejuvenescence of 

 plants, has discussed the part played by periodicity in 

 normal development with great thoroughness and clear- 

 ness.^ In the whole plant and also in the sej^arate orders 

 of branches the vigor of life goes up and down. The in- 



Fig. 6i. Chelidonium ma jus plenum. A, a normal flower 

 with four petals ; B and C, flowers with five petals ; D, a 

 flower with eight well-developed petals and two petaloid 

 stamens. 1-5, the transition between stamens and petals. 



dividual strength of the plant is perpetually fluctuating, 

 affecting the size of the leaves, the length and thickness 

 of the internodes, the number of leaflets in compound 

 leaves, the number of rays in the umbels, the ramifica- 

 tions in the inflorescences, the number of florets in the 



^A. Braun, Verjiingiing, pp. 23-55. 75-76. 90 etc. See further: 

 Heinricher. Biolog. Ccntralhlatt, Vol. XVI. No. i. pp. 13-14. Po- 

 KORNY, Sitcbcr. d. Acad. d. Wiss., Vienna, 1875, Vol. 72, pp. 527-547. 



