480 
Bulletin Xo. 1(32.—1915. 
In a later paper Cuenot (1900), presents much fuller data. He 
reports G5 broods of homing pigeons in all of which he made certain 
that both eggs were from the same female. The results were: 17 
broods, both males; 14 broods, both females; 34 broods, a male and a 
female. By chance, as, for example, by tossing two coins, the 
expectation for 64 throws would be two heads 16 times, two tails 16 
times and a head and a tail 32 times. He points out, however, that 
we must take into account that there were 6S males and only 62 
females; correcting for this, chance distribution gives the expectation 
of both males 17.7 times, both females 14.7 times, and one of each 32.4 
times, which is almost exactly the result obtained. It is therefore 
necessary he concludes, to abandon the fallacy of the bisexuality of 
the broods, beyond what would be expected from chance. 
Further observations caused him to alter also his earlier conclusion 
as to the proportion of cases in which the first egg produces a male. 
The first egg was marked before the second was laid in 30 cases, and 
both squabs were dissected two days before they were due to hatch. 
In 15 of the cases the first egg produced a male, and in the other 15 
cases a female. It appears also, therefore, to be a matter of chance 
whether the first egg laid is male or female. Cu6not thinks it prob¬ 
able that Flourens did not make his observations himself, but trusted 
to a subordinate. 
At the time we began our observations we were unaware of Cuenot’s 
work. "While the popular notions seemed a priori extremely im¬ 
probable, if they were true they presented some very interesting and 
important theoretical as well as practical problems, and it seemed 
advisable to accumulate as many data on this phase of the pigeon work 
as could be done consistently with the studies on inheritance. 
If it should prove true that there is a constant relation between 
the order of the laying of the eggs and the sex of the squabs hatched 
from them, or indeed if there should be a greater tendency in this 
direction than could be accounted for by chance, it would be necessary 
to abandon, or materially to modify, the theory which seems generally 
so well established, that sex is irrevocably determined by chance 
