4 ALICE M. BORING AND RAYMOND PEARL 
poultry at the Maine Station it has been found that there is no 
single one of the so-called male secondary sex characters which 
has not at some time been seen well developed in an otherwise 
perfectly normal female. Laying females with spurs, or with 
large, male-like comb and wattles, while not common, still appear 
every year in small numbers amongst the large numbers of birds 
in the whole flock. Females with male secondary plumage are 
rarer but still occur. Putting all our experience together we 
have come finally to the view that there is no distinct secondary 
sexual character for which the correlation with the primary or- 
gan is perfect and unvarying. 
Taking a general survey of the external characters of the birds 
in this study, and taking especially into account the shape of 
body and body carriage, they would fall into line from most 
female to most male in the same order as mentioned above, 
that is, the sum total of external characters, and particularly 
the body shape and carriage, would correspond roughly to the 
internal anatomy. They cannot be compared as to body size 
as they were not all of the same breed nor were they of the same 
age when killed for anatomical study. 
Various female birds in the Station flock, which are normal 
laying birds at times tread the other hens. Two such birds, 
K134 and M408 were studied for comparison with the abnormal 
birds. These were entirely normal females as to all external 
structural characters. 1134 was a Barred Plymouth Rock and 
Black Hamburg cross. She laid 184 eggs in 1913-14, and 84 
from October to June of 1914-15, at which time she was killed. 
M408 was a Rhode Island Red and had laid 96 eggs up to the 
time of her death which occurred before she was a year old. 
No. 1422 was a White Leghorn sent to the Station by Professor 
Atwood of West Virginia, because he thought she might be a her- 
maphrodite. Her behavior, however, at Maine was that of a 
perfectly normal female. Her egg record shows 25 eggs during 
the two months of September and October while she was at 
Maine. During the winter she laid no more and died in Febru- 
ary. There were no male second sex characters present in any 
of these birds. We shall see later in detail that this habit of 
