The time course of adult and tadpole globin production in normal animals was determined. Animals were sampled at stages 27, 28, 34, 36, 40, 41, 42, 45 , 46 (metamorph) and 1 month post metamorph, $3 animals per stage. Developmental stages of B. marinus were determined according to the method of Limbaugh and Volpe [21] . Levels of mRNA and protein were measured individually except for tadpoles at stages 27 and 28 where .10 animals were pooled due to the small size of tadpoles in the early stages of B. marinus development. 