The scheme of the classification of soil groups by Prof. STREMME (Danzig), which was presented to the last INTERNATIONAL. CONGRESS OF SOIL SCIENCE (1935), is interpleted in the preceeding paper with some critical and many explanatory notes. The soils are divided by him into the following large groups : - I. Vegetation soil type (Vegetationsbodentypen) II. Wet soil types (Nassbodentypen) III. Rock soil types (Gesteinsbodentypen) IV. Relief soil types (Reliefbodentypen) V. Artificial soils (Kunst1iche Boden) The protest of Prof. PRASOLOV (Leningrad) against this p1an, and the reply of Prof. STREMME is briefly mentioned. The former author puts stress on the morphological classification, and the latter on the genetical one. It seems to the present writer that the dispute between them will be a struggle from the different standpoints. The soils can reasonably be classified in a certain number of special ways. It will not unfrequently be possible that the doubtful case arises whether the soil in question is to be grouped into one or another type according to Prof. STREMME'S system. The wet soils are classified by him into the following five types : - A Inorganic wet soi1s (1) Valley-forest soils (Auenwaldboden) (2) Swamp-forest soils (Bruchwaldboden) (3) Marsh soils (Marschboden) B. Organic wet soils (4) Moor-margin soils (Anmoorige Boden) (5) Moor soils (Moorboden) The valley-forest soi1s occur in the elevated parts of river valleys or alluvia1 fans. The most of them are to be regarded as the "formerly wet soils" as was pointed out by v. Bulow, and are tending to change remarkably towards the brown soils or chernosems since the deforestation in past times. It is doubtful to the present writer whether such a soil can still be called the wet forest soil when the alteration far advanced, losing the majority of the original characteristics. As a whole, we are very thankful to Prof. STREMME who gave us many valuable suggestions for the examination and classification of the alluvial soils. As the supplements, the following subjects are given : (1) the writers opinion about the nomencrature of soil types, preferring the simpler morphological names to the more complex genetical ones, (2) the criticism of Prof. POLYNOV (Moscow) against the traditional russian school of soil research, and (3) the activity of the present german soil scientists who are reexamining the older methodology and terminology.

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The Colloidal clay below 0.001 mm in diameter were separated by settling method and determined quantitatively by the usual method both the total and HCI (sp. gr. 1.1) soluble constituents. The contents of silica and sesquioxides and also their molecular ratios of several representative samples are given as in the following tables. Table I. The compositions (in 100 parts of dry matter) [table] Table II. Molecular ratio [table] According to the above results both silica-alumina and silica-sesquioxides ratios of the total constituents are comparatively wide in proportion to the hot and wet climate of that island. As for the reason is chiefly attributable to the influence of parent materials rich in lime and is also presumable to the surface erosion owing to the occasional heavy rains. As the HCl-soluble constituents are much less than the tota1,the differences between them and their molecular ratios are given in table III. Table III. The difference and Molecular ratio [table] From the silica-alumina ratios of table III, the existence of clay mineral of montmorillonite type would be highly probable, as most of the crystalline clay minerals are very resistant against the action of hot concentrated HCl. After determining the combined quantity of free ferric oxide-and hydroxide by Harada's 0.025 mol oxalic acid potassium oxalate method, the author is of opinion that the silica-alumina ratio of colloidal clay is more significant than silica-sesquioxide ratio as a means of characterising soil formation Process.

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The amounts of phosphorus and potassium in the soils, available to the plant growth, were determined by the Aspergillus niger method after Niklas and were brought to be compared to the degrees of soil responses to phosphorus as well as potassium fertilization. With 38 soils from several localities the following conclusions were obtained : 1) Aspergillus niger method was not a suitable means to determine the amount of available potassium because of the fact that the growth of aspergillus micellium was influenced more by the amount of phosphorus than by that of potassium. 2) The amount of micellium was increased by adequate application of phosphorus. 3) The production of micellium by aspergillus in the soil was observed to be reversely related to the response of soil to phosphorus fertilization. 4) Aspergillus niger method was concluded to be one of the rapid laboratory tests for the determination of the amount of available phosphorus to the plant growth.

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1) Rotated barley (Naked seed) and upland rice in no manure plot, no N plot, no P_2O_5 plot, no K_2O plot, three manures plot, CaCN_2 plot, urea plot, soybean cake plot, rape seed meal plot, herring cake plot for two years (1933-1935). 2) Average temperature in the period of experiment was much the same to late 10 years average temperature, but rain fall differed more or less from late 10 years average rainfall. 3) The amount of drainage water was 55-70% average 64% to irrigation water & rainfall at barley cropping and 15-30% average 22% at upland rice cropping, and yearly 34-50% average 44%. 4) In no N plot, the growth of crops was very poor, so therefore the amount of drainage water was larger than that of other plots. 5) In CaCN_2 plot, the amount of drainage water was less than that of other nitrogenous plots. 6) pH va1ue of drainage water changed periodically between 5. 6 & 7. 5 namely high at summer time and low at winter season. Generally pH value of drainage watar was low by the addition of ammonium-sulphate. 7) The amount of various nutrients in drainage water one year per 1 ha was as follows, NO_3-N...16-34kg, NH_3-N...1-2kg, P_2O_5......0.04-0.16kg, K_2O......34-68kg CaO......75-150kg, MgO......30-80kg, SO_4......93-450kg 8) Addition of ammonium-sulphate made the reaction of soil acidic and the amount of exchangeable bases especially CaO was 1ess than original soil.

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It has been experimentally confirmed that the availability of potash for plant growth is diminished with an excess of soluble iron salts, while this undesirable effects of the latter should be removed by an adequate addition of the former. These actions depend upon not only direct effects of respective element, but mutual action or the antagonism between the elements. The authors have carried out an investigation with taro plants, Colocasia esculenta SCHOTT, which are considered to be one of the "potash-favor plants." Cosequences of the investigation are summarised as the following : 1) The antagonistic effects of K_2O to Fe_2O_3 are recognizable in the increment of growth of taro plants which are measured, by size and weight of leaf-blades, petioles and roots. The effects are less significant in earlier stage of the growth, but they are more evident in later period. 2) The antagonistic effects of K_2O display not only to Fe_2O_3 for the plant growth, but to CaO, and they doubtlessly take place to MgO. They are estimated by the ratio-values as Fe_2O_3 : K_2O, CaO : K_2O and (Fe_2O_3+CaO) : K_2O which are determined among ash ingredients, in reference to the growth of plant organs. 3) They are, also, estimated by the similar way with regard to eletrically dialysable bases of dried matter of the plant organs. It is considered that a part of the bases which are totally found among ash ingredients, is in active state from physiological view point, being movable, dialysable and transformable. While the other part of those should be in stable or fixed forms, building tissues of the plant body or settling as physiologically inactive materials. The dialysable bases are, generally, less than the non-dialysable ingredients, with a few exception of K_2O. K_2O, Fe_2O_3 and CaO are dialysed to both electrodes, showing, in general, negatively charged bases<positively charged bases by weight. These dialysable bases should be in dissociated state or ions which may be simple inorganic and so-called complex organic ions. 4) The antagonistic relationships are evidently displayed between K_2O and Fe_2O_3,CaO or Fe_2O_3+CaO in dialysable forms. Fe_2O_3 remains, particularly, in non-dialysable state to greater extent, in consequence of the antagonistic action of K_2O. 5) The antagonistic effects of K_2O to Fe_2O_3 and CaO are obvious, too, by sugars and starch which are products of the assimilation. The effects to sugars are significant in such vegetative organs as leaf-blades and petioles, while those to starch are revealed in root-tubers which are the reserve or reproductive organ. Because, the sugars are not principal reserve materials of the taro plants but are intermediate products to become higher molecular carbohydrates after polymerisation. The starch, however, is the stable reserve material in root-tubers. 6) pH of pressed juices of different plant parts have been measured by the method using quinhydron electrodes. There is found no relationship between pH values and the antagonistic effects, and also, between those and carbohydrates. 7) Specific electro-conductivity of the pressed juices prepared from the same samples to 6,have been determined after Kohlrausch's method. It has no mutual relation to the antagonistic effects of K_2O, merely showing noticiable difference between plots with and without K_2O. Degree of the specific electro-conductivity of juice is in order as leaf-blades<root-tubers<petioles.

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Sixty one soil sampls were analyzed for their vanadium contents. All sampls but two contained vanadium The highest was 0.054% and the smallest, 0.002% and the average for all the soils was 0.018% as V_2O_5. This is nearly half of the contents gained by ROBINSON in twenty six american soils.

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