Steady-state hydrodynamical equation for north-south direction without disregarding non-linear terms of field accelerations was transformed into a Fredholm's integral equation of second kind. Numerical solution was obtained without much difficulty. It was then examined what would be the magnitude of meridional velocity corresponding to an assigned vertical velocity. It was found that the relationship between the meridional and vertical velocities is not simple, being connected through a parameter similar to Reynolds' number involving the depth of the ocean, velocity and coefficient of eddy viscosity. Some discussions thereof were made.
A simple model of vertical flow was assumed and the correlation between the vertical and meridional flows was discussed.

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Nonliving organic particles (particulate and aggregate matters) in the East China Sea and its adjacent waters are examined by using a staining method with common histological reagents. Acid fuchsin, Millon's reagent, α-naphtol and Sudan Black B are successful reagents for the staining. The sizes of particles stained by acid fuchsin are generally ranging from 0.04×10³μ² to 0.9×10³μ²-1.6×10³μ² (6 to 30-40 microns in diameter), and particles, larger than 4×10³μ² are not so common below the layer of 150 m in the oceanic waters. Maximum values of the number of particles are clearly observed in this study. Generally speaking, the maximum peak of particles stained by acid fuchsin is observed at every station in the water column just below the surface, viz, at depths of 50 to 150 m in the oceanic waters, but in the shallow waters of the continental shelf of the East China Sea the maximum appears at intermediate layers almost in the middle of the depth from the surface down to the sea bottom. As for the minimum value, no consistent tendency is observed.
Presence of proteinous particles is also detected in the deep waters, and some of the particles are larger than 7×10³μ². The small lipid granules in the sea water are found by the staining with Sudan Black B, and particles stained by α-naphtol are also detected.
The vertical and horizontal distributions of these particles are discussed. A tendency, that the number and the area of particles stained by acid fuchsin decrease more clearly than those stained by Millon's reagent, is observed in a station.
The quantities of particles are greater than those reported in former works of other authors. This fact also suggests that the staining method is usefull for the detection of organic particles in the sea.

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A description is given of a simple bottom-net designed to collect zooplankton from the immediate vicinity of the sea-floor. The gear consists of a net, sled, and releasing equipment. The net has 70 cm by 70 cm in opening square and 350 cm long, and is towed on sandy or muddy bottom at a speed of 1.5 to 3.5 knots. Besides a number of new mysids and decapods, some rare crustacea species were collected in Sagami and Suruga Bays. They have hardly been obtained by ordinary plankton tow-nets. An epiplanktonic chaetognath Sagitta nagae was abundant on the sea-floor of 20 m depth in the daytime.

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The distribution of marine microorganisms was investigated in the Seas of Hiuchi and Bingo.
The results obtained are as follows:
1. The counts of total heterotrophic bacteria are 10²-10⁴ cells/ml in sea water and 10⁴-10⁶ cells/g in bottom muds, and those of nitrifier, nitrate reducer and nitrogen gas former in bottom muds are 10²-10⁵ cells/g, 10⁴-10⁶ cells/g, and 10⁰-10³ cells/g, respectively (by the M. P. N. method). As to the percentages of the bacteria to total heterotrophic bacteria, ammonia assimilator, nitrate reducer. chitin decomposer, and vitamin B₁₂ producer are about 5-50%, and the nitrogen gas former is about 5% or less (by the percentage method).
2. The count of sulfate reducer and the content of sulfide in bottom muds are comparatively large, i.e. 10³-10⁴ cells/g and 7-70 mgH₂S/100g, respectively. The results seems to indicate that the seas are effected by organic sewage and therefore the bottom muds are comparatively high reducing condition.

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This paper discusses the response characteristics of a remote sensing sonic wave gauge which measures wave height from a shipboom 7.5 meters high above the sea surface. It is operated by an echo-ranging method, using pulsed audible sound of 7 kHz at a sampling rate of 14 per second.
The measurement of long-crested waves generated in a water tank by the sonic wave gauge indicates that the apparent profile of a wave is distorted so that crests look flatter and troughs sharper and that the shorter the wave length is the smaller the measured wave height is. This distortion is due to the finiteness of the cross-section of the sound beam at the sea surface which is estimated approximately to be 1 meter in diameter. The results of observations of sea waves measured by the sonic wave gauge is found to agree well with those measured by a capacitance gauge in the frequency range lower than about 0.5 Hz.

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