30 Latent and Semi-Latent Charaeters. 



curve of a half race can be tran formed into a l)ilateral 

 curve by selection and high nutrition. 1 shall recur to 

 this point shortly. 



The well-known researches of Fritz IVIuller with 

 Abu til on give instances of half curves.^ Muller ob- 

 tained the following figures from a culture with seeds 

 from flowers with six petals: 145 with 5 petals, 103 with 

 6, and 13 with 7. Of more recent investigations we may 

 mention those of Bateson and Pertz with Vcroniea 

 Bu.vbauniii according to which the normal cases always 

 composed 70-90% of the culture in spite of the selection 

 of the extreme variants in petal-number as seed-])arents, 

 the remaining 30-10% being composed of abnormal cases 

 in a rapidly diminishing series.^ The fruits of Aquilecjia 

 are pentamerous, but 6-, and still more rarely 7-merous, 

 ones occur. The fruit of the cotton is also pentamerous, 

 but I have found several tetramerous and occasional 

 trimerous ones. Papaver Argemone has tetramerous 

 flowers, but specimens with 5, and less often with 6 

 petals, also occur ; by sowing seeds from the latter I was 

 not able to obtain any increase in the number. 



Du]:)lications of leaves, concrescence of umbel-rays in 

 Ufnhelliferae, of the fruit stalks of Cruciferae, of the 

 fruits themselves in the Conipositae and so forth, the 

 adnation of an axial bud wnth its axillary branch and a 

 number of other anomalies behave as half races. The 

 abnormal cases, which are of course infinitely rarer than 

 the normal ones, become rarer in proportion as they de- 

 part from the normal. It is unnecessary to give a longer 

 list here, I may just mention the catacorolla on the outer 



* Hermann Muller, Die Befnichtiing der Bhimcn, p. 450. 



^ W. Bateson and Miss D. F. M. Pertz, Notes on the Inheritance 

 of Variation in the Corolla of Veronica Buxhaumii. Proceed. Cam- 

 bridge Phil. Soc. Vol. X, Pt. II, p. 78. 



