44 Latent and Scnii-Latcnt Characters. 



ine o-enerall\', favorable conditions favor the characters 

 of the race, and unfavoral)le ones those of the species (see 

 below, § 26). 



This is only a special case of the well-known prin- 

 ciple: Every injury increases the tendency to atavism.^ 



In the first place let us consider the periodicity. The 

 nnm])cr of multipartite leaves increases with the indi- 

 vidual strength l30th on the whole plant and on the sep- 

 arate branches. And if, at the end of growth, weakness 

 supervenes this number again decreases. 



Let us examine Fig. 5. It is a photograph of a strong 

 young branch which was removed on August 1, 1900. 

 The lowest leaf was nearly withered ; it was small and 

 had the inversely egg-shaped form of the leaflets which 

 is characteristic of the leaves of the young red clover, 

 It consisted of only 3 leaflets. The two following leaves 

 were markedly larger and stronger, of a more elliptical 

 form and tetramerous. Then follows a 6- and then a 

 7-merous leaf, after which the leaves again return to the 

 simpler types. 



The branch photographed was chosen for its regu- 

 larity ; and yet a pentamerous leaf is absent from the 

 ascending series. Most of the branches, even on the best 

 plants, were less regular: indeed it often happened that 

 tetramerous leaves were succeeded by some trimerous 

 ones, and so forth. ^ 



What has been stated concerning the lateral branches 

 is also true of the rosette of radical leaves whose axis 



^ That is, reversion of the race to its parent species, for the cliar- 

 actcr of the race is itself, morphologically speaking, a reversion to 

 a more remote ancestor. 



^For exact figures the reader is referred to: Ueher die Periodin- 

 fdf dcr partiellen Variationen, in Ber. d. d. hot. Ges., 1899, Vol. XVII, 

 p. 48. 



