The suitability of Tricaine methane sulphonate,
urethane and ether as anaesthetics for Xenopus laevis was
investigated. Tricaine was found to be the best of these
anaesthetics and a suitable dose /body weight relationship
Frequency of feeding was shown to have no effect on
spermiation and the secondary sex characters of male
Xenopus over a period of months.
The proximity of other animals of the same or a
different species was shown to inhibit spermiation and the
secondary sex characters of male X. laevis. The evidence
suggests this effect is due to inhibition of adenohypophyseal
Nuptial pads (gloving) in male Xenopus was shown to
Ìbe controlled by testicular and adrenocortical hormones
which are secreted under adenohypophyseal stimulation.
Evidence was obtained which suggests that there are
two pituitary gonadotrophins in Xenopus; one which
stimulates gametogenesis and the other which stimulates
the secretion of a gonadal steroid.
A inhibiting effect of the gonads on the secretion of
adenohypophyseal gonadotrophin has been found.
A well controlled technique for investigating invitro
ovulation of excised Xenopus ovaries has been
developed. Ovaries have been shown to ovulate in-vitro
in response to a number of steroids as well as to luteinizing
gonadotrophins and adrenocorticotrophic hormone
(A.C.T.H.). This is the first report of in-vitro
ovulation of excised Amphibian ovaries in response to
oestrogens. It is postulated that ovulation in Xenopus
is caused by an ovarian steroid secreted as a result of
In-vivo ovulation has been shown to result from
injection of adrenocorticosteroids, methyl testosterone
and projesterone but not in response to injected
oestradiol or A.C.T.H. Hydrocortisone has been found to
inhibit the ovulatory response of female X. laevis to a
subsequent injection of human chorionic gonadotrophin
Cloacal hyperaemia in female Xenopus has been shown
to be controlled by an ovarian hormone secreted in
response to stimulation by an adenohypophyseal hormone.
Ovulation is only stimulated by a gonadotrophin with
luteinizing properties but a gonadotrophin with follicle -
stimulating activity is more potent in stimulating cloacal
Gloving, which is essentially a male secondary sex
character, was found to be present in some female X.
laevis. This gloving is not under the control of the
ovaries. Evidence is provided which suggests that it is
developed under adrenocortical stimulation.