618 
Varietäten, Descendenz, Hybriden. 
neither parent was musical, either, none of the children wäre 
musical, or, a few were musical and most were not; when one 
parent was musical and the other not, either, none of the children 
were musical, or, about one half of them were musical and one 
half were not. Tabular pedigrees of three families are given to 
illustrate these cases. The observations suggest that the musical 
sence is a Mendelian character, recessive to the non-musical cha- 
racter. R. P. Gregory. 
Hurst, C. C., On the inheritance of Eye-Colour in Man. (Proc. 
Roy. Soc. Lond., Ser. B. (Vol. 80. pp. 85—96. 1908.) 
The author finds that distinct discontinuit}^ exists between: 
1) Eyes in which two kinds of pigments are present; the one, yellow 
brown in colour, deposited on the outer or anterior surface of the 
iris; the other, blue-black in colour, deposited on the inner or pos¬ 
terior surface of the iris. And 
2) Eyes in which the posterior pigment alone is present. To the 
former type the author gives the name “duplex”, the latter he calls 
“simplex”. In general, eyes that would be called brown are duplex, 
while many of the blues and some of the greys belong to the 
simplex type. 
Three distinct patterns of duplex eyes are found, namely: ä) 
The self-coloured duplex, in which the anterior pigment is dis- 
tributed over the whole of the anterior surface of the iris. b) T h e 
ringed duplex, in which the anterior pigment is confined to a 
ringed area around the pupil. c) The spotted duplex, in which the 
anterior pigment occurs in the form of blotches or spots, irregularly 
scattered over the iris. 
In all three kinds of duplex eyes, variations in shade occur, 
depending of differences in the degree of anterior pigmentation; but 
eyes presenting grades of anterior pigmentation so low that they 
can be mistaken for simplices have not been met with. 
The inheritance of the two types of eye is Mendelian, the duplex 
type being dominant. 
Of the 139 matings which came under Observation, 20 were 
matings in which both parents had simplex eyes, 50 were matings 
in which both parents had duplex eyes, and 69 matings in which 
one parent had duplex, the other simplex, eyes. 
From the 20 matings of simplex X simplex, 101 offspring 
were produced, all simplex. 
The 50 matings of duplex X duplex fall into two groups: ä) 37 
families produced 195 offspring, all duplex; b) 13 families produced 
63 offspring, of which 45 were duplex and 18 simplex. 
The 69 matings of duplex X simplex also gave two kinds of 
results: a) 17 families produced 66 offspring, all duplex; b) 52 families 
produced 258 offspring, of which 121 were duplex, and 137 were 
simplex. 
The author gives detailed tables showing the sesults of all 
the matings. R. P. Gregory. 
Lidfopss, B., Ueber das Studium polymorpher Gattungen. 
(Botaniska Notiser, p. 241—261. 1907.) 
The author gives some considerations on the study of elemen- 
tary species. He shows that it is necessary to go the experimental 
way, if one wishes to obtain a true idea on the forms within the 
