ABSTRACT
This work was undertaken initially in order to obtain normal standards of comparison for the pattern of nitrogen excretion during wound healing and regeneration in earthworms. The main interest in the results, for the present purpose, lies in the contrast between the patterns of nitrogen output in the two species. The pattern of excretion in Lumbricus is quite well known, from the studies of Lesser (1908), Delaunay (1934) and his colleagues, and Cohen & Lewis (1949a, b, 1950); there is also some information about Pheretima (Bahl, 1945, 1947) and about some representatives of other classes of the Annelida (see Prosser et al. 1950), but none of these results have anticipated the great contrasts here observed between two rather closely related genera. A certain amount of work has been done also on Allolo-bophora caliginosa (Savigny), but this will not be described in detail.
