A further study of the growth of parts in palaemon carcinus.

Male and female prawns (Palaemon carcinus) were classed into groups according to carapace length, which was the standard adopted.The lengths of separate segments of pereiopods 1, 2, 3 and 5 were measured and their means calculated for the different classes.In the second pereiopod, the cheliped, the growth centre is in the dactylus in the female and in the propus in the male. But in young females it appears that the growth centre is in the propus and in young males in the dactylus.The difference between the rates of growth of the various segments in both males and females was slight in most cases, those in the male being consistently higher than those in the female.The lengths of the second and last abdominal segments were also measured. In both males and females growth was found to be negatively heterogonic, but growth was in each case more rapid in the female than in the male.