212
WILLIAM C. YOUNG
properties associated with the secretion of androgens, i.e., the accumulation and disappearance of cholesterol-positive lipids in the cytoplasm
of the cells, are common to all.
The structure of the fish ovary differs from that in other vertebrates
(135, 136, 139); nevertheless, Hoar (136) states that an inner granulosa
and an outer theca are probably potentially present in all. According to
Hoar the theca interna probably produces estrogens, as in mammals.
Ball (140), on the other hand, while acknowledging that decisive evidence of the endocrine function of any type of cell in the ovary of bony
fishes has not been produced, points out that the cells of the theca do not
contain lipid droplets or cholesterol and their appearance never approximates that of the cells of the theca interna of mammals and birds, which
probably are estrogen-secreting elements in members of these phyla.
He marshals impressive evidence for the suggestion, originally made
by Kinoshita (141) and by Bretschneider and Duyvene de Wit (142),
that granulosa cells in the atretic follicles (corpora atretica) are the
source of ovarian steroid hormones. We presume from the histochemical
observations reviewed by Chieffi (130) that not only are the granulosa
cells in the preovulation corpora lutea of Torpedo a source of steroid
hormones, but that the granulosa cells in the postovulation corpora lutea
of Scyliorhinus also have this role.
Important in looking at the problem comparatively, are the facts
that the cellular origin of ovarian steroids in mammals has not yet been
resolved satisfactorily (143-146),
but that prototypes of the elements
considered as sources of these hormones in mammals are present in
fishes.
V. Amphibians
Probably because of the conspicuous clasping reflex of male anurans
during the breeding season, frogs and toads were among the first animals
to be used in tests of the relationship between the gonads and mating
behavior. Many of the early experiments are described in Lipschiitz'
Internal Secretions of the Sex Ghnds (147). Much of the work done
more recently is cited by Dodd (123) in his review of the gonadal hormones and secondary sex characters in the lower vertebrates.
Descriptive accounts of the behavior of anura (148-157)
and
urodeles (158-161) are relatively numerous. Types of behavior associated with hormonal action are the breeding behavior and a migrating
behavior from land to the ponds in which they breed. The former
consists of vocalizations by both sexes, amplexus or clasping which is
done by both sexes but which is subject to a strong seasonal modification
in the male, oviposition, ejaculation by the male and his release of the
WILLIAM C. YOUNG
properties associated with the secretion of androgens, i.e., the accumulation and disappearance of cholesterol-positive lipids in the cytoplasm
of the cells, are common to all.
The structure of the fish ovary differs from that in other vertebrates
(135, 136, 139); nevertheless, Hoar (136) states that an inner granulosa
and an outer theca are probably potentially present in all. According to
Hoar the theca interna probably produces estrogens, as in mammals.
Ball (140), on the other hand, while acknowledging that decisive evidence of the endocrine function of any type of cell in the ovary of bony
fishes has not been produced, points out that the cells of the theca do not
contain lipid droplets or cholesterol and their appearance never approximates that of the cells of the theca interna of mammals and birds, which
probably are estrogen-secreting elements in members of these phyla.
He marshals impressive evidence for the suggestion, originally made
by Kinoshita (141) and by Bretschneider and Duyvene de Wit (142),
that granulosa cells in the atretic follicles (corpora atretica) are the
source of ovarian steroid hormones. We presume from the histochemical
observations reviewed by Chieffi (130) that not only are the granulosa
cells in the preovulation corpora lutea of Torpedo a source of steroid
hormones, but that the granulosa cells in the postovulation corpora lutea
of Scyliorhinus also have this role.
Important in looking at the problem comparatively, are the facts
that the cellular origin of ovarian steroids in mammals has not yet been
resolved satisfactorily (143-146),
but that prototypes of the elements
considered as sources of these hormones in mammals are present in
fishes.
V. Amphibians
Probably because of the conspicuous clasping reflex of male anurans
during the breeding season, frogs and toads were among the first animals
to be used in tests of the relationship between the gonads and mating
behavior. Many of the early experiments are described in Lipschiitz'
Internal Secretions of the Sex Ghnds (147). Much of the work done
more recently is cited by Dodd (123) in his review of the gonadal hormones and secondary sex characters in the lower vertebrates.
Descriptive accounts of the behavior of anura (148-157)
and
urodeles (158-161) are relatively numerous. Types of behavior associated with hormonal action are the breeding behavior and a migrating
behavior from land to the ponds in which they breed. The former
consists of vocalizations by both sexes, amplexus or clasping which is
done by both sexes but which is subject to a strong seasonal modification
in the male, oviposition, ejaculation by the male and his release of the