330px ship med.jpg from discovery reports 1935 1936 discovery reports discoveryreports11inst 1935 1936 fig 180 b d fig 181 the phytoplankton concentration increases so that a is caused to migrate during the day into layer y it will now follow the path a3 4 a5 a6 to c now let us suppose there is a further increase in the phytoplankton making the organism a migrate into the layer z so that it now follows the path ag 7 as a9 if now we consider the same set of con ditions but consider three organisms spaced out at a b and c in fig 181 in three days time they will be at a3 bz and ca an t1jecp jpg View Photo