TWO CASES OF PATTERN-BALDNESS 
The same individuals are shown in each picture. 
The man at the right (upper, in the second 
picture) had heavy, coarse, curly hair until twenty years ago, when he began to lose it very 
gradually. His father had the same pattern of baldness; his mother’s family had thin 
hair but no baldness. 
the age of 19, and his son developed the same pattern at the same age. 
grandmother of the man here shown was bald. 
From the two families traced definite 
conclusions cannot be drawn as to the 
inheritance of the amount of hair. 
Number of individual hairs and tex- 
tures are probably inherited separately, 
the appearance of amount being de- 
pendant on both. 
The families which were traced in 
reference to baldness show that it is 
inherited as a sex-limited trait. It is 
dominant in men, is inherited directly 
from father or mother to son, but is 
recessive in women. Apparently a du- 
plex condition in women is necessary 
to bring it out. This is the same condi- 
tion that Thos. R. Arkell found in the 
inheritance of horns in sheep.? 
Partial baldness sometimes occurs in 
women in case there is illness in addi- 
tion to a simplex inheritance. Where 
there is not the tendency to baldness 
the hair is slightly affected by poor 
health and sometimes falls out, but is 
regained upon the recovery of good 
health. Moreover, as has already been 
stated, some individuals in very poor 
health do not lose any hair. 
2 Arkell, T. R. 
“Some Data on the Inheritance of Horns in Sheep.” 
The lower individual has thin, straight hair; baldness appeared at 
The maternal 
(Fig. 3.) 
In one family, unfortunately not 
charted, the father became very bald 
before he was thirty. His only son 
showed the exact pattern of his father’s 
baldness at birth. The only hair on 
the head was in a fringe above the ears 
and at the back. Later hair came in 
on the top of the head, presenting a 
normal appearance. The boy is now 
nineteen years old and is beginning to 
lose hair above the forehead. This 
seems to indicate that the pattern is 
present at birth. 
Congenital baldness must not be 
confused with pattern baldness. In 
the former there is no hair whatever, 
eyebrows are lacking and nails are 
poor or faulty. Instead of hair there 
is sometimes a downy fuzz. One family 
observed has shown this trait for the 
three generations about which anything 
is definitely known. The grandfather, 
father and mother were completely 
bald from birth. The seven sons and 
one daughter have never had any hair. 
The only grandchild, son of the oldest 
boy, also shows the same peculiar trait 
New Hampshire 
Agricultural Experiment Station, Bull. 160, May, 1912. 
349 
