92 Dr John Struthers on Variation in the Number - 
daughters have had four sons and four daughters, being the fourth 
generation, all of whom were normal. A fifth generation in this sub- 
group consists as yet of only two boys and two girls, who are also 
normal. 
In this sub-branch, we see the variety of the first generation pre- 
sent in the second, passing over the third and fourth, and also the 
fifth as far as it has yet gone. 
(6) James, had three sons and two daughters who are normal. 
(c) Thomas, had four sons and five daughters who are normal; 
and has two grandsons, also normal. 
In this sub-branch of the descent, we see the variety of the first 
generation, showing itself in the second and third, and passing 
over the fourth, and (as far as it as yet exists) the fifth generation. 
(d) John L (one of the informants) had six fingers, the addi- 
tional finger being attached on the outer side, as in the case of his 
brothers James and Thomas. All of them had the additional digits 
removed. John has also a sixth toe on one foot, situated on the 
outer side. The fifth and sixth toes have a common proximal pha- 
lanx, and a common integument invests the middle and distal 
phalanges, each having a separate nail. 
John L has a son who is normal, and a daughter, Jane, who 
was born with six fingers on each hand and six toes on each foot. 
The sixth fingers were removed. The sixth toes are not wrapped 
with the fifth, as in her father’s case, but are distinct from them, 
The son has a son and daughter, who, like himself, are normal. 
In this, the most interesting sub-branch of the descent, we see 
digital increase, which appeared in the first generation on one limb, 
appearing in the second on two limbs, the hands; in the third on 
three limbs, the hands and one foot; in the fourth on all the 
four limbs. There is as yet no fifth generation in uninterrupted 
transmission of the variety. The variety does not yet occur in any 
member of the fifth generation of Esther’s descendants, which con- 
sists, as yet, only of three boys and one girl, whose parents were 
normal, and of two boys and two girls whose grand-parents were 
normal. It is not known whether, in the case of the great-great- 
grandmother, Esther P , the variety was original or inherited. 
16. Case of Additional Thumb, with distant Hereditary Origin. 
B—— et. 3, Linlithgowshire, was born with an additional 
thumb on the left hand, which Dr Hamilton removed when she was 
a few months old. The upper end of the proximal phalanx was 
left, for security to the metacarpo-phalangeal joint, and has since 
grown to some extent. It was not much smaller than the thumb 
which was left. The only other child, also a daughter, is normal. 
The mother’s maternal uncle (W ) had a thumb of the same 
kind, which Dr Hamilton has seen. His five sons and five daughters, 
however, were normal. The mother of the girl B is one of a 
family of four brothers and five sisters, all of whom are normal, and 
