MARINE BACTERIA AND THEIR RÔLE IN THE CYCLE OF LIFE IN THE SEA III. THE DISTRIBUTION OF BACTERIA IN THE OCEAN WATERS AND MUDS ABOUT CAPE COD

A considerable number of investigations concerning the number of bacteria and their distribution in sea water have been made. Among the earliest of these was that of Russell (1892, a and b, 1893), who conducted systematic studies of the distribution of bacteria in the Gulf of Naples. He found bacteria in small numbers to be uniformly distributed in the water at distances of 3 to 15 kilometers from shore and at depths ranging from 50 to 1,500 meters. It was found by others (Cassedebat, 1894; de Giaxa, 1899) that while the water of harbors and bays might contain large numbers of bacteria, this number, as determined on the ordinary solid bacteriological media, became very small at comparatively short distances from shore. Bassenge and Fischer (1894, a and b), who investigated the water oven a wide area of the Atlantic Ocean, found bacteria in larger numbers than have any other investigators. The largest numbers, however, were found near land or in the presence of lange quantities of floating sea weed. Lloyd (1930), in her investigations in the Clyde Sea area, followed the distri bution of bacteria at five stations during the course of a year. In the rather shallow waters of this region, the surface water was found to be richest in bacteria, the number decreasing with depth but usually in creasing slightly again at the bottom. The numbers in the surface water fluctuated considerably but no definite seasonal trend could be detected; below the surface the numbers were remarkably constant throughout the year. Numerous, usually somewhat fragmentary in vestigations, ranging from polar to tropical waters, have almost in variably shown small numbers of bacteria to be present in the sea water. Among these may be cited those of Frankland and Burgess (1897), Levin (1899), Otto and Neumann (1904), Gazert (1912), Berkeley (1919) and Lipman (1929). The results of recent investigations such