T IE respiration of the parts of the imphibian gastrula has been studied by many investigators. The work has been directed along three lines of inquiry: first, to learn whether the organizer has a higher respiratory activity than the presumptive epidermis; second, to map the respiratory pattern of the gastrula; third, to determine the nature of the relationship between the distribution pattern of yolk and the respiratory pattern of the gastrula. The results of investigators are contradictory. In view of the fact that the parts of the gastrula, the age of the gastrula, the reference standards, the species of Amphibia, and the techniques used differ from worker to worker, the confusion is not at all surprising. There is need for a reinvestigation of the whole problem, not only to clear up the confusion, but also to establish a basis for further research on the metabolism and biochemistry of the parts of the gastrula and their relation to differentiation.