4. HORMONES AND BEHAVIOR
233
degree of feminization seen by Grady and Phoenix remains to be tested.
The results from many experiments indicate that estrogens and
androgens organize patterns of behavior in fishes, amphibians, and
birds. The "männliche Sexualinstinkt" was displayed by genetic female
Platypoecilus sp. and the medaka, Oryzias latipes, raised from the day
of hatching in aquarium water containing methyltestosterone (20, 23,
24). The sex-reversed XX female medakas took the role of males, mated
with normal XX females, and were fertile producing female (XX)
progeny. Genetic males (XY) were transformed into XY females by the
addition of estrone or diethylstilbestrol to the aquarium water (19, 21,
22). Matings of the XY females with normal XY males were fertile. If
the reversals were permanent, as the reader is left to infer, an organization of behavior occurred comparable with and actually more extensive
than that obtained in the guinea pig and rat. The point can be ascertained with certainty only if the behavior of sex-reversed individuals is
tested following gonadectomy and controlled replacement therapy. In
this respect work with the guinea pig is more advanced than that with
lower vertebrates.
The display of heterotypical sexual behavior must be assumed to
occur when sex reversal in adults is spontaneous as it may be in the
swordflsh Xiphophorus hellen (397-400)
and in several other species
(122, 135, 401). Masculine behavior by females of a number of species
is also reported after treatment of older animals with androgenic substances (23, 24, 402-404),
after ovariectomy and the regeneration of
testicular tissue (405, 406), and after ovariectomy and the implantation
of testicular tissue (403). It would be interesting if we could know from
this work on adults, whether the effects were permanent and whether
there had been any alteration of the responsiveness to male or female
hormones. The only hint that the effects were permanent and that the
administered hormone had on organizing action is contained in the
statement by Okada and Yamashita (403) that once formed, the acquired male characteristics do not disappear readily even after the
implanted methyldihydrotestosterone must have lost its effectiveness.
At the other extreme, a loss of plasticity is suggested by Laskowski (23,
24), who stated that adult female Platypoecilus variatus when treated
with methyltestosterone exhibited only the preliminary male courtship
patterns. Precopulatory and copulatory behavior were not seen.
The point should be noted that in all the reports of investigations in
which adult fishes were studied, the reversal of behavior was from that
of the female to that of the male. Not enough work has been done to
reveal whether reversal in the opposite direction can be obtained with
the same facility, is easier, or is more difficult. From the belief expressed
233
degree of feminization seen by Grady and Phoenix remains to be tested.
The results from many experiments indicate that estrogens and
androgens organize patterns of behavior in fishes, amphibians, and
birds. The "männliche Sexualinstinkt" was displayed by genetic female
Platypoecilus sp. and the medaka, Oryzias latipes, raised from the day
of hatching in aquarium water containing methyltestosterone (20, 23,
24). The sex-reversed XX female medakas took the role of males, mated
with normal XX females, and were fertile producing female (XX)
progeny. Genetic males (XY) were transformed into XY females by the
addition of estrone or diethylstilbestrol to the aquarium water (19, 21,
22). Matings of the XY females with normal XY males were fertile. If
the reversals were permanent, as the reader is left to infer, an organization of behavior occurred comparable with and actually more extensive
than that obtained in the guinea pig and rat. The point can be ascertained with certainty only if the behavior of sex-reversed individuals is
tested following gonadectomy and controlled replacement therapy. In
this respect work with the guinea pig is more advanced than that with
lower vertebrates.
The display of heterotypical sexual behavior must be assumed to
occur when sex reversal in adults is spontaneous as it may be in the
swordflsh Xiphophorus hellen (397-400)
and in several other species
(122, 135, 401). Masculine behavior by females of a number of species
is also reported after treatment of older animals with androgenic substances (23, 24, 402-404),
after ovariectomy and the regeneration of
testicular tissue (405, 406), and after ovariectomy and the implantation
of testicular tissue (403). It would be interesting if we could know from
this work on adults, whether the effects were permanent and whether
there had been any alteration of the responsiveness to male or female
hormones. The only hint that the effects were permanent and that the
administered hormone had on organizing action is contained in the
statement by Okada and Yamashita (403) that once formed, the acquired male characteristics do not disappear readily even after the
implanted methyldihydrotestosterone must have lost its effectiveness.
At the other extreme, a loss of plasticity is suggested by Laskowski (23,
24), who stated that adult female Platypoecilus variatus when treated
with methyltestosterone exhibited only the preliminary male courtship
patterns. Precopulatory and copulatory behavior were not seen.
The point should be noted that in all the reports of investigations in
which adult fishes were studied, the reversal of behavior was from that
of the female to that of the male. Not enough work has been done to
reveal whether reversal in the opposite direction can be obtained with
the same facility, is easier, or is more difficult. From the belief expressed