STANFORD UNIVERSITY ee
MEDICAL CENTER a Prev

PALO ALTO, CALIFORNIA

SCHOOL OF MEDICINE DEPARTMENT OF GENETICS
Professor J. Lederberg, Executive

See the enclosed references, All I have on horses
is Comfort's note ~~ he finds no effect of paternal
age (in a small sample).

Cavalli is also working on the effect of grandparental
age on the sex ratio to measure the spontaneous rate of
mutation for X-borne recessive lethals,

An ind&x to abstracts on sex ratio appears in the

12/60 Am J Human Genetics,