Regeneration and the Moulting Cycle in Blattella Germanica L. II. Simultaneous Regeneration of Both Metathoracic Legs

Abstract

At 29[degree]C, 70% relative humidity, simultaneous removal of both metathoracic legs at the proximal autotomy plane in first instar Blattella germanica results in the appearance at the first molt of either a symmetrical pair of differentiated regenerates or a symmetrical pair of undifferentiated papillae, but not of intermediate stages in differentiation. Papillae at the first molt are followed by differentiated regenerates at the second. Simultaneously produced regenerates are not distinguishable from those arising from unilateral operations. The first molt of simultaneously regenerating animals is not delayed when a pair of papillae is produced, but a delay somewhat greater than the age of the animal at operation is associated with appearance of a pair of regenerates at the first molt. The second molt of simultaneously regenerating animals producing papillae at the first is delayed by about one day. Comparison with unilaterally regenerating animals shows a slightly but significantly increased delay in molting related to simultaneous regeneration. This is probably due to increased demands for metabolites in producing 2 regenerates, added to the disturbance of endocrine balance already postulated from experiments on unilateral regeneration.