No. 580] ORIGIN OF SINGLE CHARACTERS 



233 



eries to the zoologist and paleontologist is that what 

 we zoologists describe as a " single character," the horn 

 of a sheep or of a titanothere, for example, is probably 

 the expression of a very large number of germinal "de- 

 terminers" all of which are necessary in the germ to 

 produce the horn. If only one of these "determiners" 

 should change the character of the horn would change, 

 or the horns might be lost altogether. Thus the germi- 

 nal correlation of "determiners" to produce what ap- 

 pears as a single character to the zoologist and paleon- 

 tologist is visibly represented in the bodily correlation 

 of the horn with a very elaborate offensive and defensive 

 mechanism including all the bony and muscular charac- 

 ters necessary to operate the horn effectively, as well as 

 the psychic desires and impulses to use the horn. We 

 thus have a vast array of internal and external, of struc- 

 tural and functional correlations with this single charac- 

 ter, the horn. 



10. Conception of the "Least Character" 

 In the beginning of this address I noted that no one 

 has ever undertaken to define the "character." 



It is very difficult if not impossible to define one of 

 these least characters as observed in living and fossil 

 series even when reinforced by the experimental evi- 

 dence of heredity. A definition may be essayed through 



Zebu (Bos indicus) was introduced to the cow Gayal (Bibos frontalis), and 

 a female hybrid was born October 29, 1868 (A of pedigree). This animal 

 (A) produced her first calf June 17, 1872, a second one October 16, 1873, 

 a third one January 5, 1875, a fourth March 11, 1876, a fifth November 2, 

 1878; these five calves were the produce of this female hybrid Gayal with 

 the Zebu bull. She was now introduced to the male American Bison (Bison 

 americanus), and on May 21, 1881, she produced a female No. 2 (B of 



"This remarkable animal, the result of the triple alliance, was last year 

 introduced to the bull Bison, and on March 12, 1884, she produced a female 

 (C of pedigree). This last individual, now eleven weeks old, is undistin- 

 guishable from a pure-bred Bison of the same age. ' ' 



