GENETICS 179 



he shared the common prejudice regarding " good nourish- 

 ment." 



Tn the case of the dimorphic cowslip, Darwin says the 

 increasing fertility in successive generations after what he 

 terms " illegitimate fertilisations " was such that it seemed as 

 if they were becoming "habituated to it," i.e., as I would say, 

 an inferior habit under . a retrograde compatibility 

 established itself, and the apparent " success" is only that of 

 retrogenesis (i.e., the quasi-fertility is as illegitimate as the 

 mode of fertilisation). 



But do types retrogressively arising really deserve the 

 name of "Hero"? Does the term not apply more aptly to 

 cases of self-sterility which we have already viewed as a 

 means of checking an abhorred self-fertilisation? Darwin 

 tells us that self-sterility runs to a certain extent in groups, 

 and that it differs much in degrees in different plants. In 

 those extraordinary cases in which pollen from the same flower 

 acts on the stigma like a poison, "it is almost certain," he 

 says, " that the plants would never yield a single self-fertilised 

 seed." This resistance to degenerative influences this 

 striking antagonism of a bio-economically useful and superior 

 to a relatively wasteful and inferior behaviour seems to be 

 nearer the source of heroism and honour than a yielding to the 

 temptation of unproductive self-fertilisation. 



Dies Leben 1st der Giiter hoechstes nicht, 

 Der Ubel grosstes aber, 1st die Schuld. 



Orchids are among the most unproductive of plants, and 

 some varieties existing in Nature, such as Ophrys apifera, 

 regularly fertilise themselves. The same must be said of 

 certain cleistogamic plants, which produce an abundance of 

 cleistogamic flowers, "but are very rarely capable of cross- 

 fertilisation." 



Most species of orchids in the equatorial regions live as 

 epiphytes or parasites on living or dead vegetables. Their 

 "heroism " is of a very questionable kind. 



N 2 



