HYBRIDISM AMONG COCKATOOS. 25 



parent. Thus, the former parent (Cacatu a in the present 

 case) would appear to be prepotent over the latter parent 

 ( L i c m e t i s ) . 



There is exhibited, as a rule, no simple Mendelian relation- 

 ship in the hybrids between animal species. The characters 

 of the parents tend to blend, and often they blend very 

 thoroughly as in the cockatoos: and although the hybrid 

 may be nearer in certain characters to one parent than 

 to the other, yet hi no cliaracfer />■• flie direct injhience of 

 either parent apparently absent. No character observed 

 could be described as "dominant" or "recessive," unless 

 these terms are used in a popular sense, and a dominant 

 character is simply a prepotent one. It is true that the 

 Mendelian relationship concerns characters only find not 

 individuals as a whole. Thus, supposing that the hybrid 

 cockatoos were capable of crossing among themselves and 

 that the Mendelian mode of inheritance occurred, then the 

 offspring would not be wholly like C. galerita or wholly 

 like L. nasica, but some of them would very strougly 

 resemble one or the other of the paient forms in some of 

 their characters. According to tlie Mendelian conception of 

 hereditai'y transmission by definite unit-characters, ever}' such 

 character is capable of being replaced by an alternative, and 

 by the discovery of the alternatives (Allelomorphs) the exact 

 nature of the units can alone be determined. A character 

 like stature or other dimension of an animal is obviously a 

 complex one which could not be expected to follow the 

 Mendelian mode of inheritance as a whole, unless groups of 

 characters are supposed to be capable of remaining connected 

 together in some obscure manner and of being transmitted as 

 a single character. 



Blended inheritance is the antithesis of exclusive inheri- 

 tance : and in the case of the latter the Mendelian relation- 

 ship can be readily understood on the simple and ingenious 

 supposition propounded by Mendel of the segregation of i he 

 gei-minal cells. The extreme jMendelian school tend to deny the 

 existence of real blended inheritance ; they attempt to explain 



