HOMOLOGY AND ITS INTERPRETATION 47 



derlying structural uniformity; (2) it is of such magnitude that 

 it cannot be ascribed to variation within the species; (3) it 

 has been appropriated by the hereditary process, in the sense 

 that it is now an "inherited" character based on the trans- 

 mission of specific germinal factors. 



Now it is claimed that for the occurrence of this kind of 

 modification in conjunction with homology only one rational 

 explanation is possible, and that explanation is evolution. If 

 this contention be a sound one, and Dorlodot, who claims 

 certitude for the evolutionary solution, insists that it is such, 

 then, in the name of sheer logical consistency, but one course 

 lies open to us. We cannot stop at Wasmann's comma,^ we 

 must press on to the very end of the evolutionary sentence and 

 sing with the choristers of Woods Hole: 



"It's a long way from Amphioxus, 



It's a long way to us; 

 It's a long way from Amphioxus, 



To the meanest human cuss. 

 Good-bye fins and gill slits; 



Welcome skin and hair. 

 It's a long, long way from Amphioxus, 



But we came from there." 



In this predicament it will not do, as we shall see presently, 

 to adopt Mr. McCann's expedient of balancing anatomical dif- 

 ferences against anatomical resemblances. To do so is to 

 court certain and ignominious defeat. We must, therefore, 

 examine the argument dispassionately. If it be solid, we must 

 accept it and give it general application. If it be unsound, 

 we must detect its flaws and expose them. Intellectual hon- 

 esty allows us no alternative! 



Moreover, in weighing the argument from organic homology 

 we must not lose sight of the two important considerations 

 previously stressed: (1) that the inference of common an- 



'Rev. Erich Wasmann, S. J., accepts the evolutionary inference from 

 homology as regards plants and animals. When it comes to man, how- 

 ever, he attempts to draw the line, and argues painstakingly against the 

 assumption of a bestial origin of the human body. 



