For the purpose of revealing whether or not hemoglobin synthesis is inhibited by the AMD, the author estimated the hemoglobin level of AMD treated anilmals by microspectrophotometer, and found that the hemoglobin
levels of all the developmental stages of erythroid cells were not inhibited by the AMD. The data indicated that about one half of mRNA for hemoglobin is synthesized in the early stage of specialization with the supplementary synthesis at the later stages and all these mRNA is stable
and insensitive to AMD.</p