The stimulation of the fish goiiad with extracts of fish hypophj-ses has been reported by-several investigatoi*s (Roussay, '31; Pereira and Cardosa, '34; Cardosa, '34; Haslcr et al., '39 ; Matthews, '39). The administration of' mammalian gonadotropins to fish and closely related forms have, l i o ~~e v e r , protluced inconsistent and often negative results (Young and Hellcrby, '35 ; Artenioff, '36 ; Hansen, '39 ; Johiison and Riddle, '39 ; hlattliews, '39 a ) , but comprehensive studies are lacking. Positirc effects Iiavc been reported by others (Calret, '32 : Bouclicr ct al., '33 ; Schrciher, '36 ; Castelnnovo, '37 ; Kahn, '38 ; Ihowles, '31)).
S o general conclusions can be drawn from the above findings. We undertook, therefore, to study fiirther the respoiise of a tcleost fish, Leljistcs rcticulatus (guppy), to several goiiadotropica substances of manimalian origin. It was liopcd hp such a study i o reveal first whether the fish gonad is responsive to the various mammalian gonadotropins, and secondly, if so, to deterniine whether different elements in the gonad, or gametogenic and endocrine functions, could be independciitlp stimulated, as hy tlie various FSH and LH principles in inammals.
The aulhor wishes to acknowledge the helpful criticism of Dr. Rohert Gaunt, under whose direction this work was undertaken, as well as the adrice and suggestions of Dr. Harry A. Cliaripper.