-. i Jo' rf Cf4'd do* n'b'da d'ei'd B'dV J^'Jd'a o"

■ dddddddd'ddn'dn'd'DdB'^d'ddoy'ed'Hd

d ^.

/ ^/ *^m tmtJmm C* Um^'l, nw%_^ W.

Eugenics Record Office, Cold Spring Harbor. Long Island, N. Y. SCALE .7

A. A Geneology Chart Showing the Actual Pedigree of Pre-Senile Lamellar Cataract.

1. Following the practice of tracing only one trait on one pedigree chart, this chart traces

the trait of pre-scnile lamellar cataract. All individuals of the family tree are plotted even though all do not show the trait.

2. It would be fairly easy to construct a chart tracing the family distribution of a trait

by following the principles exemplified in the above diagram.

n

■ • Wh.K Forclotk

DO Nc Wh.H FcfloiK

I 1 1

t?

V ■ • o

s

fy^ ^ ^

Ti

9-r9

OB D D O

« 7 S « 10

h

II. the firii recorded ancestor liavinn a white forelock. H-l, liis son inherited the while forelock And married a woman without it. ill. of their five sons three inlierited tlic white torek>ck and two did not. IV. ««howinn the four daug-hters of one son, III-J, tliree ilaiiRhters havinn inherited the white forelock and one lias not. V. sliowinf; the children of these four daugliters who married men without a white forelock : some of the cliildren of each of the three mothers possessing the white forelock have inlierited it but none of the children of the other tuotlier not possessing it have the white forehnk.

Lyle Fitch "Inheritance of a White Forelock," The Journal of Heredity, Novemtwr, 193 7, American Genetic Auociation, Washington, D. C. SCALE .9