Ovulation in adult amphibians has been experimentally induced by hypophyseal transplants or by administration of extracts of the hypophysis in a number of species by various workers. Wolf' succeeded in producing ovulation out of season in frogs by nieans of homoplastic transplantation of anterior hypophysis. Houssay, Giusti, and Lascano-Gonzalez2 and Houssay and Giusti3 were able to bring about a similar response in toads by the use of homoplastic implantations of anterior lobe. The results obtained by Noble and Richards" on the salamander Eurycea bislineata, in which ovulation has been induced by means of homoplastic transplants, are confirmed by the findings of Adamssp who was able to obtain egg-laying in adult Triturus viridescens and Triton cristntus by the same means. Similar results were observed by Adams7* if heteroplastic transplants from anurans were substituted for the homoplastic implants. Adams' was also able to confirm the earlier findings of Houssay et a1 on ovulation in toads, in being able to elicit the response only with homoplastic transplants of anterior lobe substance.Ovulation has likewise been produced in anuran amphibians with extracts of the mammalian hypophysis. Through the adininistration of an alkaline aqueous extract of the anterior lobe of cattle, Kehl" induced ovulation in the mature frog, Discoglossus pictw, and Adams' using a similar extract obtained the same response in frogs. Up to the present time there appears to be no record of -Wolf, 0. p., pBI)c. SW. EXP. BIOL. AND MEI)., 1989, 86, 692. 2Houssay, B. A., Giusti, L., Lascano-Gonzalez, J . M., Rev. SOC. Argent. Bwl., 3Houssay, B.
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THREE FIGURESLillie ( '16, '17) and Keller and Tandler ('16) were the first to offer a plansihle explanation of the sex-modification occurring in the free-martin. Few cases have been described with transformations in the male direction greater than those observed previously by these authors. Especially is this true of the external genitalia as the number of cases exhibiting a definite effect on the external organs is indeed limited.Keller and Tandler ( '16) observed modifications of the external genitalia in the male direction, hut give no descriptions. Keller ('22) describes a case in which the female external genitalia were replaced by a short, spigot-like phallus perforated by n urethra. A free-martin, described by Numan (1843)' with a set of apparent female external genitalia partially transformed in the male direction is illustrated by Lillie ('17). According to Lillie, the Numan free-martin exliibitcd a degree of transformation greater than any in his series. Another case of special interest is presented by Fraser Itoberts and Greenwood ('28) who describe a free-martin with extreme male-like modification of the genitalia. I n addition to the usual modifications, this animal had a penis-like body traversed by a urethra and a prostate gland.
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