446 Tricotylous Races. 



tlie earlier seeds give different values from those given 

 l)y the later ones? Has the character of tlie year in 

 which the harvest is made any such influence amongst 

 perennial plants? Obviously these cjuestions must be 

 answered if the individual harvests are to be limited in 

 the interest of the experiment. 



In the last two sections of the first part of this vol- 

 ume we have seen that semi-latent characters manifest 

 a certain periodicity in their distribution over the plant, 

 and also that the choice of seeds on the plant plays some 

 part in the process of selection. The question is, how 

 do the tricotylous races behave in this respect? 



The general rule seems to be that a bud, whether of 

 a branch or of a flower, is more likely to reproduce an 

 anomaly, the more vigorous it is (p. 324). Therefore 

 with an increase in the degree of branching the expecta- 

 tion of the occurrence of anomalies decreases (p. 329). 

 The first or lower fruits of an inflorescence will be 

 stronger than the higher ones, and the fruits on the 

 weak lateral sprigs of the primary and secondary branches 

 may as well be thrown aw-ay. 



There is no ground for supposing that the flower buds 

 behave difl^erently from the vegetative parts. The best 

 instance of the phenomena in question is afforded by 

 profuseh- branched S]:)ecimens of the twisted race, Dip- 

 sacus syh'cstris tarsus. The torsion affects the middle 

 ])ortion of the main stem, but neither its upper nor lower 

 extremity. Tt is repeated on the strongest branches situ- 

 ated on the middle of the stem, and on these only in 

 their middle parts, and excluding the weaker ones. The 

 stronger a stem or a branch is. the greater is the extent 

 of the twisted part. Tn tlie 1)ranches it is always con- 

 fined to sinHe internodes, \\liereas the stem mav fre- 



