210 ILLEGITIMATE OFFSPEING OF Chap. V. 



plan of selecting very fine capsules during favourable 

 seasons had been followed for obtaining the normal 

 standards, instead of taking, during various seasons, 

 the first capsules which came to hand, the standards 

 would undoubtedly have been considerably higher ; 

 and thus the fact of the six foregoing plants appearing 

 to yield an unnaturally high percentage of seeds may, 

 perhaps, be explained. On this view, these plants are, 

 in fact, merely fully fertile, and not fertUe to an ab- 

 normal degree. Nevertheless, as characters of all 

 ' kinds are liable to variation, especially with organisms 

 unnaturally treated, and as in the four first and more 

 sterile classes, the plants derived from the same pa- 

 rents and treated in the same manner, certainly did 

 vary much in sterility, it is possible that certain plants 

 in the latter and more fertile classes may have varied 

 so as to have acquired an abnormal degree of fertility. 

 But it should be noticed that, if my standards err in 

 being too low, the sterility of all the many sterile 

 plants in the several classes will have to be estimated 

 by so much the higher. Finally, we see that the ille- 

 gitimate plants in the four first classes are all more or 

 less sterile, some being absolutely barren, with one 

 alone almost completely fertile ; in the three latter 

 classes, some of the plants are moderately sterile, 

 whilst others are fully fertile, or possibly fertile in 

 excess. 



The last point which need here be noticed is that, 

 as far as the means of comparison serve, some degree 

 of relationship generally exists between the infertility 

 of the illegitimate union of the several parent-forms 

 and that of their illegitimate offspring. Thus the 

 two illegitimate unions, from which the plants in 

 Classes VI. and VII. were derived, yielded a fair 

 amount of seed, and only a few of these plants are in 



