Il6 THE METHOD OF DARWIN. 



similarity shall be more numerous than the 

 points of difference. The third and chief 

 reason which Darwin gave for belief in natural 

 selection, that it connected under an intel- 

 ligible point of view a host of facts, is identi- 

 cal with the reason which he gave for forming 

 and so tenaciously clinging to the hypothesis 

 of Pangenesis. And this condition the latter 

 fulfilled. It was bound to do so by the very 

 terms of its origin. A hypothesis was not 

 likely to leave Darwin's hands until it did 

 harmonize with the facts from which it had 

 taken its rise. 



The fourth reason for belief in a theory, 

 namely, that it leads deductively to new inves- 

 tigations, and through them to new facts, brings 

 up the hypothesis of Pangenesis against a wall. 

 A cause may be recognized as a working force"; 

 its claim to having produced known effects may 

 be supported by analogy; and a vast body of 

 phenomena that must be effects of some cause 

 may be brought together into harmony under 

 it. But it must also be possible to work out 

 other consequences of the theory. 



Francis Galton made a determined effort to 

 test the hypothesis. He felt the pressing 

 importance of doing so, for, as he said, "Its 

 postulates are hypothetical and large, so that 



