Chap. Y. HETEEOSTYLED TEIMOKPHIC PLANTS. 209 



as far as the less fertile plants in these three classes 

 are concerned : first, because none of the plants in 

 Class V. attained their proper height, which shows 

 that they were in some manner affected ; and secondly, 

 because many of the plants in Classes V. and VI. pro- 

 duced anthers which were either contabescent or in- 

 cluded small and shrivelled pollen-grains. And as in 

 these cases the male organs were manifestly deterio- 

 rated, it is by far the most probable conclusion that 

 the female organs were in some cases likewise affected, 

 and that this was the cause of the reduced number of 



With respect to the six plants in these three classes 

 which yielded a very high percentage of seeds, the 

 thought naturally arises that the normal standard of 

 fertility for the long-styled and short-styled forms 

 (with which alone we are here concerned) may have 

 been fixed too low, and that the six illegitimate plants 

 are merely fully fertile. The standard for the long- 

 styled form was deduced by counting the seeds in 

 twenty-three capsules, and for the short-styled form 

 from twenty-five capsules. I do not pretend that this 

 is a sufficient number of capsules for absolute accu- 

 racy ; but my experience has led me to believe that a 

 very fair result may thus be gained. As, however, the 

 maximum number observed in the twenty-five capsules 

 of the short-styled form was low, the standard in this 

 case may possibly be not quite high enough. But it 

 should be observed, in the case of the illegitimate 

 plants, that in order to avoid over-estimating their in- 

 fertility, ten very fine capsules were always selected ; 

 and the years 1865 and 1866, during which the plants 

 in the three latter classes were experimented on, were 

 highly favourable for seed-production. Now, if this 



