151 
Among the various experiments in breeding that have attracted considerable 
attention in the past have been those relative to the control of sex. Numerous 
methods have been advanced for regulating sex in offspring, of which the following 
may be given. 
(1) The right ovary and the right testicle produce males and the left females. 
(2) Early stages of oestrum produce females, later males. 
(3) A preponderance of spermatozoa will cause male sex, while a small amount 
will result in female offspring. 
(4) Alternate ova will produce the same sex. 
(5) The preponderance of sex rests with the female. 
(6) The sex is in excess according to which is the stronger, the male or female. 
(7) Sex is influenced by the activity of the function of nutrition. Where there is 
the most nutrition females occur, where least males. 
(8) Young males breed females, old males males. 
Numerous experiments have been conducted by various persons on these prob- 
lems, but thus far without securing data of a permanent character, so far as settling 
the problem is concerned. One of these experiments is of sufficient interest to be 
presented here, even though somewhat old. This is an experiment reported by 
M. Charles Girou de Buzareingues, of France/' who, on July 3, 1826, proposed to 
the Agricultural Society of Severac to demonstrate the control of sex by method of 
age — that is, that young males sire female offspring and old males male offspring. 
Two of the members of the society owning flocks of sheep placed them at the disp >sal 
of the society for conducting this experiment. 
The first experiment was conducted as follows: M. Girou recommended very young 
rams to be put to the flock of ewes from which the proprietor wished the greater 
number of females in their offspring, and also that, during the season when the rams 
were with the ewes, they should have more abundant pasture than the other; while 
to the flock from which the owner wished to obtain male lambs chiefly he recom- 
mended to put strong and vigorous rams 4 or 5 years old. 
The following table gives the result of this experiment: 
Flock for female lambs, a 
Flock for male I* 
nabs, b 
Age of dam. 
Sex of lambs. 
Age of dam. 
Sex of lambs. 
Male. 
Female. 
Male. ' Female. 
14 
16 
5 
26 
29 
21 
Two years 
7 1 
Three years 
Three years 
15 14 
Four vears 
33 14 
Total 
Total 
3-5 
18 
76 
8 
55 31 
Fiye years aud under . . 
25 24 
Total 
Total 
53 
84 
80 55 
a Two rams seryed this flock, one 15 months old and the other nearly 2 years old. There were three 
twin births in this flock. 
b Two strong rams seryed this flock, one 4, the other 5 years old. No twins here. 
Late in the same summer another French sheep breeder, in the village of Bez, took 
a flock of 84 ewes and divided it into two parts of 42 each, one part consisting of the 
strongest ewes, from 4 to 5 years old, and the other of the weakest ones, under 4 
years old or above 5. Lot I was bred to four male lambs, about 6 months old each 
and of good promise. Lot II was bred by two strong rams more than 3 years old. 
A third lot of 22 head, owned by the shepherd of the owner of the 84 ewes, were 
placed with Lot II. The results secured were as follows: Lot I dropped 15 males 
and 25 females; Lot II dropped 26 males and 14 females; Lot III dropped 10 males 
and 12 females. 
The sheep of Lot III were in better flesh than the others. M. Girou states that 
the general law, so far as we are able to detect it, seems to be, that, when animals are 
in good condition, plentifully supplied with food, and kept from breeding as fast as 
they might do, they are most likely to produce females. Or, in other words, when 
a race of animals is in the circumstances favorable for its increase, nature produces 
the greatest number of that sex which, in animals that do not pair, is most efficient 
for increasing the number of the race. But if they are in a bad climate or on stinted 
pasture, or if they have already given birth to a numerous offspring, then they pro- 
duce more males than females. 
Ann. del' Agr. Francais, XXXVII, XXXVIII; also Jour. Agr., 1828-29, pp. 63-65. 
