JOURNAL OF ACMPLTiAL RESEARCH 
Vol. XXX Washington, D. C., May 15, 1925 No. 10 
THE POSSIBILITY OF SEX CONTROL BY ARTIFICIAL IN¬ 
SEMINATION WITH CENTRIFUGED SPERMATOZOA 1 2 
By Jay L. Lish 1 
Formerly assistant in the Department 
INTRODUCTION 
The phenomenon of sex is one of the 
most conspicuous features of living 
things, both plant and animal. Dif¬ 
ferentiation of the reproductive organs 
into two sorts, the one called male and 
the other female, is almost the univer¬ 
sal rule among all but the very sim¬ 
plest of both plants and animals. 
However, a great variety of arrange¬ 
ments of the male and the female re¬ 
productive organs exists in the different 
roups of the plant and animal king- 
oms. Thus the great majority of the 
higher plants (spermatophytes) and 
many of the lower forms of animals 
have both the male and the female re¬ 
productive organs in the same indi¬ 
vidual. On the other hand, some of 
the higher plants (such as hemp, mul¬ 
berry, date palm, and many others), 
and the great majority of the higher 
animals (including practically all of 
the vertebrates and arthropods and 
many of the lower animals), have the 
male reproductive organs in one indi¬ 
vidual and the female organs in an¬ 
other. 
Sex is popularly considered as a 
feature of the animal kingdom alone 
and is scarcely associated with plants. 
Although this idea of the existence of 
sex is biologically wrong, it is econom¬ 
ically sound because all but a few 
of the plants of economic importance 
are monoecious, while all of the mam¬ 
mals, birds, and insects are normally 
dioecious, and there is frequently a 
considerable difference in the value of 
the two sexes^ of economically impor¬ 
tant animals.' 
This article considers the problem 
of sex control in the light of what is 
now known about the mechanism of 
sex determination and gives a de¬ 
tailed report of an experiment carried 
out at the Wisconsin Agricultural 
of Genetics, University of Wisconsin 
Experiment Station to test the possi¬ 
bility of controlling sex by artificial 
insemination with centrifuged sperma¬ 
tozoa. This experiment resulted in 
the discovery of a number of interest¬ 
ing facts, especially in regard to the 
success and methods of artificial in¬ 
semination and in regard to the varia¬ 
tions in the size of the spermatozoa. 
It did not succeed in its primary pur¬ 
pose of controlling the sex of the off¬ 
spring thus produced, but the results 
of the experiment do throw some light 
upon the possibility of sex control by 
such a method and are therefore pre¬ 
sented here. 
DEFINITIONS 
The term “sex determination” is 
used here to mean the process which 
determines that any given individual 
shall be of a definite sex—that is, 
male, female, or some grade of her¬ 
maphrodite. It is an observed fact and 
must have a mechanism upon which 
it rests whether or not that mechan¬ 
ism is as yet clearly demonstrated. 
The term “sex control,” on the other 
hand, is used to mean the modification 
of the process of sex determination 
so that the offspring will be of the sex 
which the breeder desires. The con¬ 
trol of sex among the higher non- 
parthenogenetic animals has not yet 
been completely demonstrated, and 
it is quite possible that even a com¬ 
plete knowledge of the mechanism 
of sex determination will not lead to 
any successful method of sex control— 
that is, the problem of sex determina¬ 
tion has a solution which may be com¬ 
pletely demonstrated at some future 
time and probably has already been 
found in the chromosome theory of 
sex determination or some modifica¬ 
tion of it, but the problem of finding a 
practical method of sex control need 
not necessarily have any solution. 
1 Received for publication July 23, 1924; issued July, 1925. Paper No. 50 from the Department of 
Genetics, Agricultural Experiment Station, University of Wisconsin, published with the approval of the 
director of the. station. 
2 Now Animal Husbandman, Texas Agricultural Experiment Station. 
Journal of Agricultural Research Vol. XXX, No. 10 
Washington, D. C. ■ May 16,1925 
Key No. Wis.-29 
52205—25t-1 
( 893 ) 
