CHAP, xvin A "FAIRY TALE OF SCIENCE"? 229 



germ plasm may hand on the duty of building up a 

 body to some of the more newly formed material, and, 

 evading the chances of death, may refuse to quit the 

 parental tissues till the moment of fertile sexual inter- 

 course. It is potentially immortal ; practically, by 

 the law of chances, it will be both mortal and short- 

 lived. If pollen grains depend on the wind or depend 

 on insects for doing their work, how much potentially 

 immortal "germ plasm." must die in the history of 

 every dioecious plant ! 



Unicellular creatures, however, are immortal, accord- 

 ing to "Weismann, rather qua non- sexual than qua 

 unicellular. Sex and death are somehow correlated; 

 he believes that he has proved this by showing a general 

 correspondence between the age at which species pro- 

 duce offspring and their natural term of life. This view 

 of Weismann's is widely accepted. A correlation be- 

 tween the fact of sex and the habit of dying a natural 

 death is largely admitted. 



Death, then, as a natural and certain event, arose 

 with sex, or in consequence of it. But how did sex 

 originate ? Romanes asserts a self-contradiction in 

 Weismann, because at one time he says that the origin 

 of sex was due to natural selection, at another time that 

 it could not be. In Weismann's system, natural selec- 

 tion works upon the materials furnished to it by sexual 

 reproduction upon the new varieties thus invented 

 upon the new permutations or combinations of germ 

 plasm, thus manifested, and brought up for judgment 

 in the form of offspring. Still, I see no reason why 

 natural selection should not sit in judgment upon sex 

 itself, if sex somehow originated. No doubt the admis- 

 sion must then be made that Weismann's clear theory of 

 variation had ceased to be available. Sex explains other 



