236 GBOEGB JOHN EOMANES 1886- 



higher Cryptogams and lower Phanerogams ; Herma- 

 phrodite species {i.e. male and female organs in the 

 same flower) occur much more frequently among 

 higher Phanerogams. 



There is, besides, another difficulty. According 

 to Weismann and yourself, it is natural selection that 

 has brought about sexuality ' for the sake of better 

 results in the offspring,' by making them more 

 variable or plastic. But how can natural selection 

 act prophetically? Unless the variability is of use to 

 the individuals at each stage of its advance, it cannot 

 come under the sway of natural selection, however 

 advantageous it may eventually prove to the type. 

 But, if one thinks about it, how can such variabihty 

 be of any use to the individual ? Observe, beneficial 

 variability is quite different from beneficial variation. 

 It is the tendency to vary that is in question, not the 

 occurrence of this, that, and the other display of it. 

 Now, I do not see how sexuality can have been evolved 

 by natural selection for the purpose of securing their 

 tendency in the future, when it can never be of any 

 use to individuals of the present. Bach individual of 

 the present is an accomplished fact ; the tendency to 

 produce variable offspring is, therefore, of no use to it 

 individually, and so natural selection would have no 

 reason to pick it out for living and propagating. 

 Such is my difficulty touching this point. Another 

 is, why do we meet with such great differences be- 

 tween (sometimes) allied natural genera, and even 

 whole natural orders, as to the facility with which 

 their constituent species hybridise ? For example, 

 species of genus Geranium will hybridise almost better 



