Notropis perpallidus, a New Minnow from Arkansas

dry season refractoriness of the Brazilian fish. Additional pituitary substance introduced by injection overcomes this refractoriness in both species. On the other hand our studies with rainbow trout showed that this species could be made to spawn at least two months in advance of the normal spawning time, provided injections are started that early. Our work here, however, did not include experiments to show if this were possible with muskellunge. While this work is of considerable physiological importance there are also certain features which make the methods here used of value in the conservation and management of fish populations in streams obstructed by dams, permitting the preservation of this species until arrangements can be made for fishways to be constructed around the dams, allowing them to pass to natural spawning grounds.