Hurlin: Inherited Syndactyly in Man 
iy 
INHERITANCE OF WEBBED FEET IN THREE GENERATIONS 
The shaded symbols indicate the persons having webbed digits. 
In the first generation, the 
father transmitted the character to his only son, who in turn transmitted it to three of his six 
children—two sons and a daughter. (Fig. 24.) 
yond the first joint by fleshy parts. 
The inheritance is represented in 
Figure 24, in which squares indicate 
males, circles females, and shading the 
presence of the web. The trait cannot 
be traced back of the paternal grand- 
father, who is represented by the shaded 
square in generation I in the diagram. 
He had transmitted it to his only child, a 
son, who passed it to half of his off- 
spring. Of the six children in genera- 
tion III, two sons and one daughter 
exhibit the web. The Mendelian ex- 
pectation happens to have been ex- 
actly fulfilled. 
The web is known to have been well 
defined in the case of the grandfather. 
In the father the condition is described 
as similar to that shown in the photo- 
graph, with slightly greater extent on 
Sex Arrraction,| by Victor C. 
Vaughan, Sc.D., M.D.,ILL.D., pro- 
fessor of hygiene and physiological 
chemistry, and dean of the University 
of Michigan School of Medicine, 
AnnArbor, Mich. Pp. 44, price 50c. 
St. Louis, C. V. Mosby Co., 1920. 
the left than on the right foot. In the 
third generation, in child number 3 
the condition is that photographed; in 
number 6 the web is somewhat less 
pronounced; and in number 4 it is re- 
ported as distinct but not especially 
noticeable. 
This inheritance occurs in a branch 
of an old New England family whose 
genealogy has been fully investigated 
and published. The grandfather here 
mentioned was one of ten children and 
his father one of six. Yet it has not 
been possible to discover that this sup- 
posedly dominant trait occurs in any 
of the collateral lines. The possibility 
is suggested that the trait may fre- 
quently exist, as happens in one mem- 
ber of this third generation, as a slight 
and not particularly noticeable web. 
In this lecture Dr. Vaughan de- 
scribes briefly the evoluton of sex and 
the basis of the physiological attraction 
between the sexes in the human species 
at the present time. The point of 
view is that of the eugenist. Empha- 
sis is laid on sex education, and proper 
sexual selection. 
