Local factors and regeneration in Crustacea.

The role of normal innervation in the regeneration of crustacean appendages has been illustrated in previous papers (Needham, 1945, 1946); it may, perhaps, be termed the 'central' factor in regeneration. In the present paper 'local' factors, such as properties of the tissues near the site of amputation, have been studied. The results of earlier work, chiefly on Amphibia, Planaria and Oligochaeta (Korschelt, 1927, pp. 639-40), have suggested that the rate of regeneration varies with (1) the extent of tissue damage at the site of amputation and (2) the amount of tissue removed. These two factors have been studied in the present experiments on the regeneration of the 7th thoracic limb of Asellus aquaticus (L.).