82 University of California Publications in Zoology. [Vol.6 



mutual relations of the facts of Meristic Variation will also be- 

 come mere evident."' The last part of this quotation undoubt- 

 edly indicates that Bateson recognized, in a general way at least. 

 thai the significance of merism reaches beyond the phenomena of 



variation alone. The implication in the last sentence especially 

 is that meristic variation is itself only a part of the more general 

 phenomena of merism. And this implication is still clearer in 

 other statements, particularly those touching views of merism 

 for the treatment of the problems of homology and phylogeny. 

 Nevertheless it is worthy of note that not only did Bateson 's 

 immediate aims not call upon him to go into the subject from 

 any other standpoint than that of variation, but that he was not. 

 at any rate at the time of writing his book, quite clear as to what 

 sort of a road one would be traveling who should attack the sub- 

 ject from the more commanding- standpoint. "In introducing 

 the method of the Study of Variation I have said that it can alone 

 supply a solid foundation for inquiry into the manner by which 

 one species arises from another. The facts of Variation must 

 therefore be the test of the way in which organ arises from organ, 

 and that thus Variation is the test of homology" (p. 30). To 

 my mind this last sentence shows the author with compass and 

 log out of true, and off the straight course on which he was sail- 

 ing when he wrote the sentences about the identification of meta- 

 meric segmentation with merism. It is impossible in this paper 

 to give the grounds for my belief on this matter. Nor would I 

 have my reference to Bateson 's really monumental book misun- 

 derstood. My purpose is primarily not to criticize but to ac- 

 knowledge and commend: not to show where Bateson fell short, 

 hut rather how far beyond accepted views he actually went. 



This sally Batesonward I leave by calling attention to the 

 fact that resemblanu and not difference is in reality always the 

 practical test of homology: and furthermore that .Meiidelian 

 inheritance, the field in which Bateson himself has recently la- 

 bored with so much brilliancy, furnishes one of the most con- 

 vincing blocks of evidence to this effect. "What in last analysis 

 can we say about dominance but that as regards certain charac- 

 ters a particular individual plant or animal resembles one of its 

 parents more than it does the other? We may. it is true, become 



