486 
Bulletin No. 162.—1915. 
yj 
yy 
This table contains also other records of known sexes, thus giving the 
complete total of sexes determined to that date, but the ratio obtained 
from these numbers has already been discussed on (p. 465). The 
first egg laid is designated the “A” egg, while the second is egg “B; 
similarly the squabs from the two eggs are designated “A” and ‘‘B 
according to the respective eggs from which they hatched. In case 
both eggs were laid before they were found, so that the order of laying 
was unknown, or if it was not determined which squab hatched from 
which egg, they are referred to as eggs “X” and “Y” or squabs “X” 
and “Y” to designate this fact. It is a part of the daily routine to 
mark the newly laid eggs. In the work at the Rhode Island Station 
one of the eggs was removed to the incubator a day or so before it 
was due to hatch; the squab hatching from it was marked by a 
thread tied loosely around the leg, and was then returned to the nest. 
The thread was removed when the permanent legband was put on at 
the age of 10 to 15 days.* 
The first four columns of Table III record the cases in which the 
sex of both A and B are known; in the next four columns only one, 
either A or B, is known, the other egg having been sterile, accidently 
broken, or the sex for some other reason indeterminable. In the 
following three columns the sex of both squabs is known, but not the 
order of laying of the eggs, or else it is not known from which egg 
a particular squab came. The following two columns show the sex of 
only one of the squabs under similar conditions; and finally in the 
last two columns are those cases in which but a single egg was laid, 
it being designated “A” accordingly. 
The results of interest in the present connection are shown in the 
combined summaries in the rows in the lower part of the table. 
Rows 5 and 6 show a total of 845 males to 803 females, or a ratio 
of 105 : 100, which we have considered as normal. By comparing 
*A much simpler method of marking young squabs for identification purposes is now employed. 
With scissors the claw of any desired toe may be clipped off on young squabs, without bleeding, and 
without causing the bird any apparent pain. If clipped back beyond the growing region this gives 
a permanent mark by which the bird may be identified through life. We depend upon it, of course, 
only until the permanent band is put on. 
