66 HEREDITY [ch. 



any rules are to be arrived at for the distribution of 

 characters among the offspring of hybrids. 



Before proceeding to consider some of the further 

 applications of Mendelian inheritance, a few examples 

 will be given of characters in animals and plants 

 which are found to be inherited according to this law. 



In plants, flower-colour, seed-colour (due to either 

 seed-coat or the contained embryo) ; production of 

 starch or sugar in seeds (maize, see fig. 8 in which both 

 forms of seed are shown on the same cob) ; hairiness 

 or smoothness (stocks. Lychnis, etc.); 'bearded' or 

 'beardless' ears (wheat); 'palm-leaf or 'fern-leaf 

 (Primula) ; long or short styles ('pin-eye' and 'thrum- 

 eye ' of Primula) ; pollen-shape, and also fertility or 

 sterility of anthers (sweet-pea). Many other examples 

 could be given ; it should be noted that several of 

 these normally occur in nature, e.g. the two flower- 

 types of the primrose. 



In animals, coloured coat and albino (many 

 mammals) ; and many other colour-characters in 

 mammals and birds ; normal and long or ' Angora ' 

 hair in rabbit, guinea-pig, etc. (some doubt as to 

 completeness of segregation) ; comb-characters in 

 fowls ; leg-feathering in pigeons ; horned and horn- 

 less condition (sheep and cattle) ; colour-characters 

 in moths, beetles, and snails. In man, several 

 abnormal conditions, and presence or absence of 

 brown pigment in the iris of the eye. 



