COLD-BLOODED VERTEBRATES 



1047 



servation in Triturus {Triton ) . Transplanta- 

 tion of testes to females was not followed 

 by masculinization of accessory sex organs, 

 but if a secondary female sex structure was 

 itself transplanted to a normal male, the 

 sexually appropriate transformation oc- 

 curred, e.g., the middorsal skin stripe of the 

 female became a dorsal crest when grafted 

 on the male. In later experiments with 

 Triton, castration and successful re-im- 

 plantation of testes (autotransplantationi, 

 and the injection of testosterone in oil into 

 adults during the nonbreeding season both 

 resulted in the development of male acces- 

 sory structures (Aron, 1924b; Fleischmann 

 and Kami, 1936). In Desmognathus, testis 

 transplants into spayed females evoked the 

 development of masculine premaxillary and 

 maxillary teeth and of abdominal, pelvic, 

 and cloacal glands (Noble, 1926; Noble and 

 Davis. 1928; Noble and Pope, 1929). 



Eeptiles 



In the juvenile box tortoise, Terrapene 

 Carolina, testosterone propionate pellets 

 stimulated the growth of claws almost as 

 large as those of adult males (Evans, 1951a) . 

 The administration of androgens to imma- 

 ture Chelydra and to two species of Pseu- 

 demys resulted in acceleration of claw 

 growth and growth of the jienis (Evans, 

 1946, 1951b, 1952a, b». 



The first successful effort to graft testes 

 into lizards seems to have been that of Re- 

 gamey (1935) in castrate Lacerta. His grafts 

 did not survive in males but were successful 

 in 3 of 25 females; in these 3 the mesonephric 

 rudiment was transformed into an epididy- 

 mis-like structure, and the mesonephric duct 

 became a vas deferens. Kehl (1944b) in- 

 jected androsterone benzoate into female 

 Uromastix during the sexually quiescent pe- 

 riod. This resulted in conspicuous growth 

 and glandular development of the oviducts. 

 (Other evidence will be presented below for 

 a "bisexual" action of the androgens in some 

 cases.) A second result (Kehl, 1938) was the 

 development of the renal sexual segment to 

 a stage resembling that of the male's sexual 

 segment at the height of the breeding season. 

 Treatment of Sceloponts with testosterone 

 and testosterone propionate stimulated 



slight development of the mesonephric rest 

 and duct in females and conspicuous enlarge- 

 ment of the male epididymis, femoral glands, 

 and hemipenes. Both the oviduct and the 

 male Miillerian duct segments also grew re- 

 markably (Gorbman, 1939; Forbes, 1941; 

 Altland, 1943) . The administration of andro- 

 gens caused growth of the epididymis and 

 sexual segment of the kidney of Eumeces 

 (Reynolds, 1943) and of the dorsonuchal 

 crest of Anolis (Evans, 1948). 



In the snake, Thamnophis, injections of 

 testosterone propionate stimulated pro- 

 nounced development of the sexual segments 

 in castrate adult males and females and in 

 intact immature snakes of both sexes (Wa- 

 ters, 19401. 



Administration of testosterone to the im- 

 mature alligator, Alligator mississippiensis, 

 evoked striking growth of the oviducts in 

 the females and of the penis in the single ex- 

 perimental male. The mesonephroi and 

 Wolffian ducts in both sexes and the phal- 

 luses of the females did not respond (Forbes, 

 1938b). Injection of older but still immature 

 alligators with testosterone propionate 

 caused conspicuous development of the ovi- 

 duct and of the male and female phallus 

 (Forbes, 1939). 



Other effects of administered androgens in 

 embryonic and immature reptiles are dis- 

 cussed in the section on "Experimental Sex 

 Reversal." 



X. External Transport of Eggs 

 and Young 



Fish 



Most fish appear to be indifferent to their 

 eggs and offspring. However, male pipefish 

 and seahorses carry the developing eggs in 

 skin pouches, whereas the eggs adhere to the 

 surface of the belly of a catfish, Platystacus. 

 The male sea catfish Galeichthys and Cono- 

 rhynchos protect the developing eggs by car- 

 rying them in their mouths (Jordan, 1905; 

 Strawn, 1958). The transport period lasts 60 

 to 80 days in Galeichthys (Ward, 1957). 



Amphibians 



In general, amphibians abandon their eggs 

 after they are laid. It is an interesting vagary 

 of nature, however, that a number of species 



