4. HORMONES AND BEHAVIOR
225
external genitalia of the female, and they may vocalize, particularly as
they walk around the female or rub against her. Often the males mount
or attempt to mount the female. Male rabbits and dogs will chase the
female, almost playfully it would seem. The copulatory phase may be
said to begin with intromission and ejaculation. Commonly ejaculation
is preceded by several intromissions and in all the species mentioned
except the guinea pig (and man) multiple ejaculations in rapid succession are the rule. Whatever the pattern in the male, measurement is
possible and scoring procedures have been devised (9, 320, 321, 324).
Preliminary or courtship behavior in the sense of behavior which is
stimulating to members of the opposite sex, is exhibited less by females
than by males. Lethargic male guinea pigs are stimulated by mounting
behavior of females which is common in this species (276, 327). Female
sheep and goats will rub their necks and bodies against the males and
stand still to receive them (322). Late in the proestrum many female
swine show a special interest in the boar and nuzzle his scrotum and
flanks. They will bite the ears lightly and occasionally mount the males.
On the day prior to estrus females will pursue the males as well as other
large objects (323). Female dogs frequently initiate spurts of running in
which the males participate. During the proestrum some bitches will
investigate the genital region of the males and mount them with the
execution of a few pelvic thrusts (320). Female cats will crouch and
posture and make treading movements which may be in response to
and oriented toward the male (325). The copulatory behavior displayed
when the female is in estrus and receptive is in the form of a lordosis or
presentation to the male. The length of time lordosis can be elicited is
measurable as is the intensity and duration of the single lordosis in the
guinea pig. The use of the latter in estimating the strength of sexual
behavior in the female was introduced by Dr. Goy (328).
Many investigators and observers of behavior have been struck by
the great variability of the patterns displayed by individuals of a species.
The late Alfred C. Kinsey made a point of this in many of his lectures
and emphasized, particularly in the study of the human male (34), that
the variation in behavior is much greater than that in structure. More
important for the endocrinologist is the observation that patterns of
behavior tend to characterize individuals and to be displayed from cycle
to cycle in females and from test to test in males (327, 329). This feature
of the response of individuals to hormones can be useful as an end point
in tests of the specificity of hormonal action. The basis for a comparison
of the effectiveness of a group of steroids might well be the faithfulness
with which patterns characteristic of individuals are restored following
glandular removal and replacement therapy (99).
225
external genitalia of the female, and they may vocalize, particularly as
they walk around the female or rub against her. Often the males mount
or attempt to mount the female. Male rabbits and dogs will chase the
female, almost playfully it would seem. The copulatory phase may be
said to begin with intromission and ejaculation. Commonly ejaculation
is preceded by several intromissions and in all the species mentioned
except the guinea pig (and man) multiple ejaculations in rapid succession are the rule. Whatever the pattern in the male, measurement is
possible and scoring procedures have been devised (9, 320, 321, 324).
Preliminary or courtship behavior in the sense of behavior which is
stimulating to members of the opposite sex, is exhibited less by females
than by males. Lethargic male guinea pigs are stimulated by mounting
behavior of females which is common in this species (276, 327). Female
sheep and goats will rub their necks and bodies against the males and
stand still to receive them (322). Late in the proestrum many female
swine show a special interest in the boar and nuzzle his scrotum and
flanks. They will bite the ears lightly and occasionally mount the males.
On the day prior to estrus females will pursue the males as well as other
large objects (323). Female dogs frequently initiate spurts of running in
which the males participate. During the proestrum some bitches will
investigate the genital region of the males and mount them with the
execution of a few pelvic thrusts (320). Female cats will crouch and
posture and make treading movements which may be in response to
and oriented toward the male (325). The copulatory behavior displayed
when the female is in estrus and receptive is in the form of a lordosis or
presentation to the male. The length of time lordosis can be elicited is
measurable as is the intensity and duration of the single lordosis in the
guinea pig. The use of the latter in estimating the strength of sexual
behavior in the female was introduced by Dr. Goy (328).
Many investigators and observers of behavior have been struck by
the great variability of the patterns displayed by individuals of a species.
The late Alfred C. Kinsey made a point of this in many of his lectures
and emphasized, particularly in the study of the human male (34), that
the variation in behavior is much greater than that in structure. More
important for the endocrinologist is the observation that patterns of
behavior tend to characterize individuals and to be displayed from cycle
to cycle in females and from test to test in males (327, 329). This feature
of the response of individuals to hormones can be useful as an end point
in tests of the specificity of hormonal action. The basis for a comparison
of the effectiveness of a group of steroids might well be the faithfulness
with which patterns characteristic of individuals are restored following
glandular removal and replacement therapy (99).