THE POULTRY BULLETIN 
[June, 
52 
By John Stockton-Hough, M. D., 
of Trenton, N. J. 
THE PREDICTION OF SEX. 
Since the publication of the above 
1 have found among my collection, 
notices of other experimenters in this 
direction. Among them are the follow- 
ing:—Dr. Sixt,t author of a manuscript 
in German, which was translated into 
English, and edited by Dr. Trail, of 
N. Y., where it was published about 
180 l-o—copious extracts from which 
may be found in Dr. Trail’s book on 
Sexual Physiology. Dr. Sixt claims 
also that by extirpating one or the 
other of the testicles he could*cause 
the production of either sex at will. 
In the number of the Scientific 
American for May 6th, 1805, p. 293, 
there appeared a notice or announce- 
ment of what was termed a “New 
Discovery of the Breeding of Sex.” 
Its author, M. de Ferrandi, says, that 
“ for several years I have been in pos- 
session of this knowledge, (i. e. that 
of ‘the breeding of sex’) and being a 
Frenchman, I had intended to com- 
municate it to the Academy of Sciences 
at Paris; but illness has prevented 
my return to France. Fearing that 
my secret may perish with me, as in 
the case of Segato, I have decided to 
publish it for the benefit of all civilized 
people.” 
“ It is the male who engenders the 
substance destined already to be of 
the masculine sex or the feminine, be- 
fore the female receives it. The right 
apparatus engenders the male, the left 
the female. By operating a partial 
castration, therefore, of the male, it is 
easy for stock raisers to procure off- 
spring all of either sex. 
“At La Hotte, near Fort Liberty, in 
Hayti, this process has been in opera- 
tion for several years, and for the 
twelve years that 1 have watched the 
result it has never failed.” 
We have now cited three respect- 
able, and, so far as we know, reputable 
authorities, who claim to have witnes- 
sed others, or proved for themselves, 
that by the extirpation of the right 
testicle, females only were engendered, 
and by the extirpation of the left tes- 
tide, males only were produced. One 
observer claims that it never failed in 
the twelve years that he watched the 
experiments, and Dr. Funkhouser has 
already been experimenting several 
years; and Sixt, more than a hundred 
years ago, claims to have always suc- 
ceeded in his numerous experiments. 
There is no theory of the produc- 
tion of the sexes which can be so 
easily submitted to a practical test as 
this one. Almost any one can extir- 
pate one testicle of a dog, hog, bull, 
colt, rabbit, cat or cockerel, and within 
a year, or at most 18 months, the re- 
sult may be known. The greater the 
number of experimenters the more 
valuable the results. Let some one 
who reads this be stimulated to try it. 
In left-handed individuals it is pos- 
sible that the functions prevailing as 
described in right-handed individuals 
may be reversed. If possible select 
those animals having the left appa- 
ratus larger and more pendulous than 
that of the right side; a condition 
which usually accompanies right- 
handedness. How far structural or 
functional peculiarities which accom- 
pany right or left-handedness in man, 
prevail among the lower animals, has 
not as yet been thoroughly investi- 
gated. We know, however, that cer- 
tain of the lower animals have one sex 
on one side of the body and the other 
sex on the other side. 
In selecting animals for experiments 
those having anything unusual in 
their formation should be rejected. 
A curious fact, related by M. Isidore 
Geoffroy Saint-Hilaire, may be found 
recorded in the Dictionnaire Glassique 
tfhistoire Nalurelle, etc., which would 
seem to indicate that the male parent 
determines the sex of the embryo. 
“A bitch, of a large race, coming 
from the St. Bernard, was covered suc- 
cessively by an ordinary hunting dog, 
and by a Newfoundland; she gave 
birth in May, 1824, to 11 pups, which 
presented the following characters 
Six of them resembled the Hunting 
dog, the other five resembled the New- 
foundland dog. These animals differed 
so much that one found it difficult to 
believe that they were of the same 
mother. The young Newfoundland 
I. 
Some additional observations on the revival 
of an old theory of the production of the sexes, 
through recent experiments, by partial castra- 
tion. 
mong the multitude of theories 
gpl that have been advanced from 
time immemorial concerning the causes 
which determine the sex of the embryo, 
none had more respectable sponsors in 
ancient times, and few have been so 
thoroughly neglected in the last cen- 
tury, as the theory embodied in the 
belief that the product of the right 
testicle of the male, impregnating an 
egg, causes the sex of the progeny to 
be male, and the semen of the left 
testicle determines the female sex. 
Columella, Varro, and other respect- 
able writers on husbandry, in ancient 
times, taught this theory, and advised 
that the testicle not desired should be 
ligated at the time the services of the 
other were needed. 
Aristotle was also of the opinion 
that the testicle of the right side de- 
termined the male sex, and that of the 
left side, the female sex. 
hi my previous paper, in the March 
number of the Bulletin, I mentioned 
the fact that Dr. Funkhouser, of St. 
Louis, had made several experiments 
on dogs, rabbits and fowls, in extir- 
pating one or the other testicle of the 
male, with a view of determining 
whether the semen from one side or 
testicle would always produce young 
exclusively of one sex, or sometimes 
of one sex and sometimes of another. 
He asserts that these experiments 
prove that the semen coming from the 
right testicle, impregnating an ovum, 
causes it to become male, and the se- 
men from the left testicle determines 
the female sex in the embryo. He 
prepared more than a score of parti- 
ally castrated males, of dogs, rabbits 
and fowls,—extirpating sometimes the 
right testicle, sometimes the left. These 
males were coupled with different fe- 
males, and in every instance, save one 
(whiph he claims he can explain), was 
the resultant embryo* of the sex he 
had expressly determined. 
t Sixt (P. F.) (of Erfurt, Germany), An Ex- 
position of the Mysteries of Nature concern- 
ing the Generation of Man and the voluntary 
choice of the Sex of the Progeny. Edited by 
R. T. Trail, and published in N. Y. (before 
1860) from the German (Manuscript of about 
1770-1800). 
*Funkhouser—Laws determining sex. Weekly 
Medical Review, Chicago, July 5th and 12th, 
and August 23rd, 1884. 1886.] 
THE POULTRY BULLETIN. 
pups were of au entirely different color 
from the others, and twice as large. 
The six that resembled the Hunting 
dog were all females, the five that re- 
sembled the Newfoundland were all 
males. This bitch had had other litters 
of pups but neverjso many at a time.” 
It. 
PREDICTION OF THE SEX FROM THE 
SIZE AND SHAPE OF THE EGG. 
Horatius Flaccus (B. II, Sat. 4. 1. 
12) expresses it as his opinion that 
those eggs which are of an oblong 
shape are of the most agreeable flavor. 
The longer eggs are those which pro. 
duce the male; the rounder, the female, 
according to Pliny (B. x. c. 74). 
The following are Horace’s lines, 
with a liberal translation by Dr. Philip 
Frances: 
Longa quibus facies avis erit, Me memento, 
Ut sued melioris, etut magis alba rotundis. 
Long be your eggs, far sweeter than the round, 
Cock eggs they are, more nourishing and sound. 
Mr. Trotter, in No. 27 of the Journal 
of the Royal Agricultural Soc. (p. 181), 
says, “ Select the round eggs, for they 
contain female birds, and reject the 
oblong shaped, for they contain birds 
of the opposite sex.” Again, “ By the 
position of the air cell at the but-end 
of the egg, those may be selected that 
will produce the male sex; in these 
the air cell is in the centre of the end. 
If the cell be a little on one side the 
egg will produce a female chick.” Mr. 
Dixon, in his work on Domestic Poul- 
try (pp. 165-169), thinks this improb- 
able; but he and all other sceptics 
agree “ that of twenty-four eggs laid 
by a single hen, the twelve largest 
would give a great majority of male 
birds, the others, the same of pullets.” 
GoiumellaJ says : “ He who desires to 
have the greater number of his brood 
cocks, let him select the longest and 
sharpest eggs for incubation ; and, on 
the contrary, when he would have the 
greater number females, let him choose 
the roundest eggs.” Pliny is of the 
same opinion; but Aristotle§ is dia- 
metrically opposed, according to some 
translators, but commentators tell us 
that this is a misinterpretation of his 
meaning. “The ground of Aristotle’s 
opinion was,” says Harvey,|| “ because 
the rounder eggs are the hotter, and 
it is the property of heat to concen- 
trate and determine, and that heat 
can do most which is most powerful. 
From the stronger and more perfect 
principle, therefore, proceeds the 
stronger and more perfect animal. 
Such is the male compared with the 
female, especially in the case of the 
common fowl.” Harvey, in continua- 
tion, very justly remarks, that the dif- 
ferences indicated are to be understood 
as referring to the eggs of the Game 
fowl; for when a certain hen goes on 
laying eggs of a certain character, they 
will all produce either males or fe- 
males. If you understand this point 
otherwise, the guess as to males or 
females, from the indications given, 
would be extremely uncertain; be- 
cause different liens lay eggs that dif- 
fer much in respect of size and figure; 
some habitually lay more oblong, 
others, rounder eggs that do not differ 
greatly from one another; and al- 
though I sometimes found diversities 
in the eggs of the same fowl, these 
were still so trifling in amount that 
they would have escaped any other 
than the practised eye. For as all the 
eggs of the same fowl acquire nearly 
the same figure in the same womb or 
mould in which the shell is deposited, 
it necessarily falls out that they greatly 
resemble one another; so that I my- 
self, without much experience, could 
readily tell which hen in a small flock 
had laid a given egg.” In conclusion 
he very wisely says: UI wish there 
were some equally ready way for the 
child of knowing the true father.” 
Cresswell translates Aristotle as fol- 
lows: “In the egg there is a differ- 
ence, for one end is pointed, the other 
| round. The round end is laid first. 
The large sharp eggs are males; those 
which are round and circular at the 
sharp end are females. (Aristot. Hist, 
of Animals., B. vi. ch. LI, p. 2.) 
Mr. Browne, in his poultry book, 
says that it is absurd to believe that 
there is any relation between the shape 
of an egg and the sex of the product, 
as the same hen always lays eggs of 
same color, shape, &c., and every one 
t De Re Rustiea. Cap. 5. Scalig. in loc. 
9 Hist. Anim. lib. vi. cap. 2 (“Long and 
sharp eggs are females, but those that are 
spherical and have a convexity close to the 
sharp end are males.”) 
|| Gener. Anion. p. 217. THE POULTRY BULLETIN. 
[June, 
54 
knows that one hen does not breed all c 
males, and another all females. While e 
it is true that there is a certain general 1 
resemblance among the eggs laid by i 
the same hen, yet we know that there 1 
is a great difference in the size of the 
same hen’s eggs, and I shall presently 
show that there is a great difference 
in the proportion of the conjugate 
diameters. 
In the year 1872 I procured 10 duck 
eggs, the majority of which were noticed ] 
to be particularly long. From these j 
30 eggs five drakes and two ducks 1 
were hatched. These two ducks and j 
one of the drakes were kept over until 1 
the next year, and in the Spring they ; 
commenced to lay. One duck laid 
perfectly white eggs, and the other 
decidedly blue eggs. The white eggs 
were larger and longer than the blue. 
The date was written on each egg the 
day it was laid and gathered, and the 
largest and shortest circumferences 
were measured and recorded. The 
greatest circumference lengthwise, of 
any white egg, was 8£ inches, the cir- 
cumference at right angles to this, 6£ 
inches. The same measurements of the 
smallest white egg was 5§ by 4T3g; this 
last was the first egg laid, the large 
egg was the eleventh laid. The tenth 
egg measured 6£ by 5f. The largest 
blue egg was 6§ by 5£; the smallest 
was 4§ by 3£. These measurements 
were very carefully and accurately 
made and recorded, and it was my in- 
tention to note the sex of the product 
of each egg as it hatched out, but un- 
fortunately I was not able to be present 
at the time they were hatched. I had 
thus tabulated the order in which each 
egg was laid, and the proportion of 
length to breadth. 
“ Experienced cultivators of the silk- 
worm are generally able to distinguish 
the male from the female cocoon by the 
more pointed ends of the former.” 
The sex of the forthcoming product is 
much more easily foretold than de- 
termined by any examination shortly 
after birth, except by dissection. This 
is also true of the hen’s eggs, there 
being no guide in either case to the 
sex of the product in its earlier days 
of existence, except, perhaps, the size, 
which is so little as to require very 
careful measurment or weighing, and 
even by this means I question very 
much if the latter method would yield 
as large a proportion of successful 
results as that of prediction. 
(Concluded next month.) 
||ttr ||etter 
ESTABLISHED 18 6 9. 
PUBLISHED MONTHLY 
BY THE ASSOCIATED FANCIERS. 
NEW YORK, JULY, 1886. 
Charles R. Harker, - - - Editor. 
THE PREDICTION OF SEX. 
By John Stockton-Hough, M.D., 
of Trenton, N. J. 
( Concluded from the March and June numbers, 
copies of which will he sent to any address for 
ten cents each.) 
III. 
THE POSITION OF THE AIR-CELL 
WITH REFERENCE TO SEX. 
is a popular notion among 
|yy| certain people in all countries 
that by determining the location or 
position of the air-cell, one may pre- 
dict the sex of the forthcoming chick. 
Columella, iu his Husbandry, and many 
other writers on rural affairs, both 
ancient and modern, have taught that 
where the air-cell is exactly in the 
centre of the large end the product 
will be a male, when it is a little to one 
side it will be a female. I think no 
importance is t<? be attached to this 
idea. One wonders why the air-cell 
should not be on one side, the weight 
of the egg, lying as it must on its side, 1886.] 
THE POULTRY BULLETIN. 
been laid at the same period, on ac- 
count of the evaporation of the humid 
part. They ought, therefore, to be 
measured; and the most accurate 
measure is that obtained by the dis- 
placement of water, the weight of 
which may, for more convenience, re- 
present the volume of the body which 
has displaced it. 
“ However, in 1826, I weighed the 
eggs themselves, after separating the 
larger from the smaller, and the 
weights obtained confirmed my ideas 
as to the relative volume. 
“ In 1827 I proceeded in thefollowing 
manner: After forming the settings 
by bringing together the eggs which 
appeared the largest, and afterwards 
the smallest, I immersed at once all 
the eggs of the same setting in a vessel 
exactly filled with water, and placed it 
in another empty vessel. The water, 
which by this immersion passed into 
the second vessel, was accurately 
weighed, and its weight represented 
the total volume of the setting. On 
dividing this weight by the number of 
eggs, I obtained a mean representation 
of volume for each egg. — 
“ To avoid all confusion, I make par- 
ticular marks with ink on each of the 
settings. I marked the chickens the 
moment they were hatched by cutting 
off one of their claws. This mode of 
marking is very simple, but care must 
be taken to renew it every fortnight, 
for the cut claw sprouts, and at length 
does not differ from the rest.” 
****** 
The following are the results of the 
experiments of 1826: 
DEMESNE OF GOUDALIE. 
Males Females 
30 hen’s eggs, of a spherical form, 
and of a mean weight of 54.33 
grammes, yielded 15 15 
60 hen’s eggs, of an elongated form, 
and of the same weight as the 
preceding, yielded 30 30 
8 eggs of spherical form, and of the 
weight 47.56 gr., yielded 7 1 
DEMESNE OF BUZAREINGUES. 
Males Females 
60 turkey’s eggs, of the mean weight 
of 69.50 gr. produced by females 
one year old, and of small size, 
yielded 40 20 
“In the latter demesne, a third set- 
ting, the eggs of which were, to ap- 
pearance, larger than those of the first, 
and smaller than those of the second, 
one would think would cause the air 
entering to rise to the highest point; 
the only way to account for its usual 
location at the larger end, is the prob- 
able greater porosity of that end—and 
as the egg loses moisture after being- 
laid the air enters the most porous 
part to take the place of the water 
lost by evaporation. 
Giron # (Observations sur la Repro- 
duction des Oiseaux domestiques) 
wished to know whether large or small, 
long or short eggs, yield most males or 
females. 
“ Rozier has asserted his having ob- 
served in turkeys that, when the ani- 
mal has issued from the egg, and 
several days after, the female is larger 
than the male; and has added, that, 
by following this indication, one need 
not be deceived as to the sex of these 
birds. But facts only prove that, 
among the largest of newly-hatched 
turkeys, there are somewhat more fe- 
males than males; and this is the only 
fact which I have yet obtained from 
my observations on the reproduction 
of these birds;” he having, through 
unfavorable weather and accidents, lost 
nearly all his turkey and duck eggs 
which were subjected to experimenta- 
tion, the common hen furnishing the 
eggs for the following observations. 
In continuing, he says : “ I could 
only compare together the eggs pro- 
duced in the same poultry yard; for 
the eggs which seem large in one place 
seem small in another, on account of 
the difference of the races, which is 
determined by that of the food. 
“It is only by their weight that the 
volume of eggs can always be judged 
of; for the largest often weigh less 
than the smallest, when they have not 
* Cited in Edinburgh New Philosophical 
Journ. Y. VI., 1829, pp. 336-340, from Annales 
des Sci. Naturelles. 69 
THE POULTRY BULLETIN 
[July, 
yielded 6 males and 3 females; and a 
fourth setting, the eggs of which were 
laid by a tufted hen, the favorite of 
the mistress of the house, and conse- 
quently well fed, produced 5 males and 
7 females. 
and, although I do not view the results 
with suspicion, I cannot warrant them. 
from immature eggs, and females from 
mature eggs. 
“Some facts seem to prove, that, 
according to the common opinion of 
housewives, it is not a matter of in- 
difference to lay down eggs for hatch- 
ing under all the phases of the moon, 
and that the result is so much the 
more satisfactory the nearer the hatch- 
ing is to the full moon. All the settings 
of the demesne of Buzareingues, in 
1827, were composed of 25 eggs. Now, 
as may be seen from the above table, 
the success of these hatchings has 
been in the following order: 1st, those 
of the 21st of May; 2nd, those of 
the 14th of May; 3rd, those of the 
28th of March; 4tli, those of the 6th 
of June. The hatching of the first 
took place on the 16th day of the 
moon; of the second on the 10th ; of 
the third on the 21st; and of the fourth 
on the 4th. The intervals between 
these periods and full moon are 2, 4, 7 
and 10 days. Might not these relations, 
if they are constant, be the effects of 
the influence of light or darkness on 
the state of agitation or rest of the 
hen ? By too much heat, the hen’s 
sitting constantly kills the young, or 
thwarts their development.” 
Mr. Tliury,t of Geneva, Switzerland, 
in 1863, announced his theory, which 
is just the reverse of the above—viz., 
females are begotten at and just after 
the menstrual period, and males are 
begotten several days after this period. 
Consequently females are begotten 
from immature eggs, and males from 
mature eggs. This latter theory has 
created more serious interest and ob- 
servation at the hands of scientists 
than any other ever enunciated. Trans- 
lations of his pamphlet exist in German 
and English, and nearly every medical 
and scientific journal has had some- 
thing to say concerning it. M. OosteJ 
the great embryologist, in conjunction 
with Mr. Gerbe, made some experi- 
ments on fowls, which he claimed dis- 
proved this theory, at least its appli- 
cability to birds. He made the follow- 
ing experiments on fowls: 
EXPERIMENTS OF 1827. 
Dates of 
Incubat'n 
3*5 
T2 * - 
!«i 
Si1.- 
Itfl 
III 
E a 
Males. 
Females. 
Observations. 
June 6. 
16 
40.76 gr. 
9 
7 
May 21. 
22 
41.15 
14 
8 
Hatched June 11, nocn. 
May 14. 
16 
43.68 
9 
7 
“ “ i. 
Mar. 28. 
13 
44.64 
6 
7 
June 6. 
6 
45.44 
5 
1 
May 21. 
20 
46.52 
10 
10 
Hat’d June 11, afternoon 
June 6. 
5 
46.88 
1 
4 
May 14. 
17 
47.04 
8 
9 
Hatched June 5. 
June 6. 
10 
DEM* 
LEC 
53.00 
SNE OP 
URE.* 
4 
6 
May 13. 
n 
49.20 
8 
3 
April 22 
10 
50.93 
6 
4 
* The hena of this demesne are larger than t iose of Buzareingues. 
DEMESNE OF BUZAREINGUES. 
“The total of these different broods 
is 183 males and 152 females. 
“If these results are confirmed by 
new and numerous experiments, as the 
volume of the eggs is in relation with 
that of the birds, it will be established, 
1st, that, in the same poultry yard, 
and under the same race of fowls, the 
larger females produce a greater pro 
portional number of females than the 
smaller; 2nd, that there is no certain 
relation between the sex of chicken 
and the form of the egg; 3rd, that the 
small eggs are longer in being hatched 
than the large; 4th, that in the gal- 
linacese the predominance of the male 
sex is greater than in the mammifene. 
Laying hens were kept separated 
from the cock for a long period—then 
a cock was penned up with them—from 
the eggs laid after the cock had been 
placed with them, chicks of both sexes 
were hatched, with no regularity in 
the order of the production of the 
sexes—sometimes males from the first 
eggs, sometimes females. 
INFLUENCE OF THE ORDER IN WHICH 
THE EGGS ARE LAID BY THE FE- 
MALE ON THE SEX OF THE BIRD 
THEY WILL PRODUCE. 
IY. 
It was also determined that a hen 
would lay fertile eggs for 10 days after 
she had been excluded from the ap- 
proaches of the cock. 
“Old hens lay large eggs, and if 
birds obey the same laws of reproduc- 
tion as the mammiferae, these eggs 
ought to yield as many males as the 
smallest. Now, it will be remarked 
that predominance of the males fur- 
nished by the small eggs is greater 
than that of the females furnished by 
the large eggs. It may also be re- 
marked, that the very young females 
which have not acquired a precocious 
development, yield a great proportional 
number of males. It is therefore prob- 
able that the same laws of reproduction 
are common to the mammiferse and to 
birds. 
It is a well-known fact that pigeons, 
doves, and all of that tribe, lay but 
two eggs, rarely three, but never more 
than two hatch, the other becomes 
addled when there are three. There 
is usually one male and one female 
produced from these two eggs, and the 
male is often hatched first; and having 
laid an egg one day she omits many 
days and then lays another. I think 
Aristotle says that the egg which pro- 
duces a male is usually laid first, or 
before the one that produces the female. 
u IJr. Hubbard, || alleges that in the 
case of the turkey hen, one copulation 
impregnates the ova laid during the 
season, or for two broods, and farmers, 
he says, inform him that the first brood 
are principally females, and the last 
brood principally males. From another 
source I have it, that among domestic 
poultry, the last eggs laid nearly al- 
ways produce the cocks of the clutch.” 
Dr. Hubbard tried some experiments 
with hens, and found that when the 
first half of a hatch of eggs laid by a 
Iii 1850 Dr. Silas Hubbard, then of 
Buffalo, N. Y., announced in the Buffalo 
Med. Jour. (1850, p. 252; Apr. 1855, 
p. 044) that in man males are begotten 
just before the menstrual epoch, and 
females just after, from which he 
reasoned that males were begotten 
t Memoire sur la loi de la production des 
sexes ehez lesplantes, les animaux etl’komme. 
Geneve, 1863, 8°, 28 pp. 
$ Memoire sur ‘‘la production des sexes.” 
Compte Rendu .des Seances de l’Acad. des Sci. 
8 Mai, 1865, pp. 941-949.; OWriX , | 
|| The Peoria Medical Monthly, June 1881, 
p. 53. 
“The comparative trial of round 
egg and long eggs was made by my 
orders, but not under my inspection; 1886.] 
THE POULTRY BULLETIN. 
hen were hatched, they principally de- 
veloped into hens, but the last halt laid 
mainly developed into roosters. 
M. Girou asserts that it is a well- 
known fact that the eggs produced be- 
fore the month of July give more males 
than those produced after the month 
of June. From his table I take the 
following figures:—Of 169 eggs laid 
before the month of July, displacing 
on an average .0441 kilogrammes of 
water, hatched out 141 chicks, 75 males 
and 53 females. Another lot of 119 
eggs, in same series, gave 37 males 
and 51 females, making 112 males and 
104 females, or, 107 males to 100 fe- 
males. From 132 eggs laid after the 
month of June, displacing on an aver- 
age .0444 kilogrammes of water, 118 
chicks were hatched, 55 of which were 
males and 61 females, or 90 males to 
100 females. 
From this same table he claims to 
show that by coupling strong cocks 
with weak hens he produced 1415 
males to 1000 females; weak cocks 
with strong hens, produced 725 males 
to 1000 females. 
In conclusion M. Girou observes, 
that one may remark in the tables that 
precede, that the relative number of 
females was not always in relation 
with the volume of the egg; and that 
a setting of 25 eggs of the smallest di- 
mensions gave 11 males and 13 fe- 
males; while another setting of 25 
eggs of larger size gave 13 males and 
10 females. It is not then, as one might 
think, the nourishment which determ- 
ines the sex of the embryo, it is already 
decided at the moment of fecundation, 
and it depends on the relative condi- 
tion of the father and the mother, or 
rather of their reproductive formations. 
* * * The volume of the egg is only a 
slight index of the state of the female 
when she receives the male, but it does 
not indicate the condition of the latter, 
and consequently one announces one 
of the terms of the relation, which 
ought to be represented in the embryo. 
I say it is only a slight index of the 
state of the female; it is, in fact, ordi- 
narily in harmony with the size, race 
and color of the hen ; notwithstanding 
a pullet, well developed and disposed 
to procreate females, produces smaller 
eggs than an old hen disposed to pro- 
create males; and the largest eggs, 
which are very often furnished by the 
oldest hens, are sometimes those which 
give the most males; from which ice 
conclude, that taking the eggs at random 
coming from hens of different ages, the 
volume of the eggs could only authorize 
feeble conjectures on the sex of the chick 
it may produce. 
To breeders of animals interested in 
the laws determining the production 
of the sexes, I commend the following 
series of books, recently published, 
which may be procured through any 
foreign bookseller: 
Janke, (H.)—Die Vorausbestimmung 
des Geschlects, beim Rinde, 8°, Ber- 
lin, 1881, 100 pp. 50 cts. 
Diising, (C.)—Die Regulierung des 
Geschlects verhaltnisses bei der 
Menschen, Tiere und Pflanzen, 8°, 
Jena, 1884, 364 pp. Costs $1.50f 
Reviewed in Popular Sci. Monthly, 
January, 1885. 
Starkweather, (G. B.)—The Law of 
Sex, 8°, London, 1883. $4.00. 
Lioy, (P.)—Sulla legge della Produ- 
zione dei Sessi, 8°, Milano, E. Treves, 
1872,362 pp. 50 cts. 
Milesian ly. — Stock-Breeding, 8vo, 
K Y.; 1879.