No. 633] INHERITANCE IN THE OSTRICH 301 



In adopting the first interpretation we depart from the 

 generally accepted opinion of biologists of the present 

 day and admit that an acquired character may become 

 transmissible ; in maintaining the second we are exercis- 

 ing a credulity unjustified by biological experience. 



In the voluminous literature of evolution and heredity, 

 case after case has been brought forward by advocates 

 such as Lamarck and Herbert Spencer, claiming to be 

 illustrations of the inheritance of acquired characters, 

 and just as surely has it seemed possible to interpret 

 them in some other fashion, as Weismann and others 

 have insistently done. The fate which has befallen these 

 should suffice to make the boldest hesitate in adducing yet 

 another. It is the apparently unassailable character of 

 the two opposing statements above which emboldens one 

 in all diffidence to re-open ''the interminable question" 

 of the late Professor W. K. Brooks, that leader and in- 

 spirer of so much American philosophical biology. The 

 peculiar justification for the present claim seems to be 

 that, were the callosities of the ostrich not transmissible, 

 they could be acquired just as effectively from the respon- 

 sive nature of the skin of the bird; also that natural 

 selection has no bearing on the question, for they are 

 adaptive structures which the organism has the inherent 

 power to produce as required. 



According to Weismann (quoted from Walter 6 ) three 

 things are necessary to prove the inheritance of ac- 

 quired characters: "first, a particular somatic character 

 must be called forth by a known external cause ; second, 

 it must be something new 7 or different from what was 

 already exhibited before, and not be simply the re- 

 awakening of a latent germinal character; and third, the 

 same particular character must reappear in succeeding 

 generations in the absence of the original external cause 

 which brought the character in question forth." It is 

 contended that all the circumstances surrounding the 

 sternal and pubic callosities of the ostrich are in full 

 accord with these three requirements. 



