1. The filamentous fronds of the algae of the genus Aegagropila often form spherical tballi or hollow balls mostly due to rolling about on the bottom when they are at the mercy of waves and currents. The ball of each species and variety differs in shape and appearance in accordance with the nature of the filaments, viz., their height, type of branching, firmness, etc.
2. The ball of Aegagropila Sauteri from Lake Akan, Hokkaido, is rather compact in texture, composed of comparatively firm filaments radially arranged, and the cells at the peripheral layers of the ball are often worn off, being rubbed against the gravels on the bed of the lake. The cells of the underlying layers gradually grow until they come out from the surface to undergo the rubbing again. Where such trimming repeats effectively we find well-finished, velvety balls.
3. In A. Lagerheimii from Lake Toba, Prov. Tonnai, Saghalien, the ball is rather flexible, consisting of soft and delicate filaments, and consequently under a less effect of friction. Thus the ball doesnot assume a spherical shape, its surface being dishevelled with decumbent filaments.
4. In two small marshes near Lake Akan, i.e., Lake Toro and Lake Chimikeppu, where the rotatory movement of water near the shore is by no means active, we do not find A. Sauteri in its normal shape, but in the forms of irregular masses which are referable to forma profunda and var. Borgeana respectively. It is hoped that we can decide the relation between those va-rietal forms and the typical one by an experiment of transplantation.
5. The ball of A. Sauteri var. Borgeana from Lake Naiho, Etorofu Isl., Kuriles, is provided often with one or more pebbles in its hollow cavity. The wall of the ball consists of one to three layers of entangled filaments. Each layer is about 5mm in thickness, woolen cloth-like in texture.
6. Above mentioned pebbles in the hollow cavity of the ball are considered to beprimarily a part of substrata on the bottom of the lake on which this alga is found to attach forming compact cushions. A small part of this decumbent cushion sometimes becomes free from the substratum through the death of many of the basal cells, while smaller pebbles often do not detach from the under-surface of the free cushion and later on are enclosed by the latter.
7. Those cushion-like fronds detached from the substrata after having rolled near the shore first become hollow spindle in shape enclosing pebbles, if they attach, and then gradually become spherical by their further tumbling.
8. When the wall of a ball is composed of two or three distinct layers, they have no cellular connection between them and are separated without difficulty, though they closely contact with each other. The inner surface of each layer is occupied by dead cells which we take as the remains of the holdfasts of the primary frond of sedentary habit. The outer of surface the inner balls is vivid green in colour, as fresh as that of the outermost.
9. In other words, we have sometimes compound balls, so to speak, composed of two or three concentric balls of different origins. The primary or innermost ball has been enclosed by the secondary one transformed de noco from a free-floationg cushion newly detached from the substratum. As a result, there is no sign of cellular connection between these two hall; showing the growth of the outer ball from the filaments at the inner. In general, the compound balls are of large diameter, being more than 5cm.

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The species is a clupeoid fish distributed from the seas of Indo-Australian Archipelago to Central Japan. Its egg having rather thick egg membrane (Fig. 1) measures ca. 1mm. in dia The spawned eggs stick to each other making cluster and adhere to the substratum in the sea, so they are not pelagic but adhesive and demersal. The yolk is translucent with some yellow tinge and has the reticulate structure characteristic to the eggs of clupeoid fishes. Artificial fertilization is rather easy. Eggs artificially fertilized hatch by 6 to 7 days at 21-23°C. Newly hatched larva has elongated form, its anus situated far backward as in the case of other clupeoids. The dorsal fin shifts anteriorly during development over a distance of about 16 to 18 myotomes, but the anus and the ventral fin scarcely change their initial situations (the anus lies at 35th or 36th myotome; the ventralfin at 20th or 21th myotome). During the development of the embryo some special blastomeres make appearance at the margin of blastoderm at early stage and later they lie rather in extra-embryonic region, so the blastoderm disc shows irregular form unlike other teleostean eggs (Fig. 2, 3). Those blastomeres persist from an early stage of the embryo until hatching or later. In some of the said blastomeres get out of the embryo and lie freely in the perivitelline space. The post-larva of the present species can be distinguished from those of other clupeoid fishes of Japan, i.e., Sardinia melanosticta (T_FMMINCK & S_CHLEGEL) and Etrumeus microps (T_EMMINCK & S_CMLEGEL, ) by the presence of the characteristic black pigments arranged along the borders between myotomes (Fig. 10-16). The silvery lateral band along the side of the body begins to appear at the stage of ca. 30mm. of the body length. (See Fig. 1-19).

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Ayu is one of the most highly priced edible fishes for the Japanese.
Recently, there is a tendency among the pisciculturists to culture this fish. But concerning its natural food few reports have been made and the complete studies have not yet been done. Hence the authors deeply felt the necessity of the study of its food in its natural conditions.
From these motives we set about to examine the contents of the digestive ducts of the fish to know its food materials.
By our study we found that the chief food of the Ayu is not merely Diatoms. as hitherto has been believed, but also Bluegreen-algae; and besides these algae, wealso found many other algae such as Green-algae (Oedogonium, Scenedesmus, Stigeoclonium), Red-algae (Chantransia) and volcanic ashes. (cf. Table I.)
But we could not find even a little bit of animal matters in it.
We may say, therefore, that the food of the Ayu in its adult stage, is really vegetable matters, and that it prefers Bluegreen-algae or Diatoms; but where both Bluegreen-algae and Diatoms grow, the Ayu takes mostly the former algae for its food rather than the latter. These observa-tions lead us to the conclusion that the Ayu seems to like Bluegreen-algae better than Diatoms.
We wish to continue further researches on the variation of its food according to its ages, on the differenciation of its food in every season, and many others.

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Attention was called in my previous works^(1)(2)(3) to the bactericidal action of monobasic fatty acids on Staphylococcus pyogenes aureus, Proteus vulgaris, Bacillus typhosus and Vibrio cholerae.
In the present paper is given an extension of my observations on the same kinds of bacteria with the same methods⁽⁴⁾ but using dibasic fatty acids instead. Incidentally monobasic and dibasic fatty acids are herein compared in this connexion.
The results obtained may be summarized as follows: - (1) Among the dibasic fatty acids of the same molecular concentration, oxalic acid (C₂) tops the list in the strength as bactericide, and malonic acid (C₃) comes the next. With increase in the number of C-atoms the bactericidal activity of the acids in question suddenly falls down from malonic acid on until C₆ acid is reached but it goes up gradually henceforth.
(2) The bactericidal action of anions is not observable in those dibasic fatty acids with 2 to 6 C-atoms, but it is the case with those having more than 6 C-atoms.
(3) Dibasic, monobasic, unsaturated, and monobasic saturated fatty acids having 2 or 3 C-atoms stand in descending order of bactericidal activity when tested with respective acids having the same number of C-atoms and the same concentration. This is chiefly due to the difference of pH values. The above-mentioned order is reversed with those having the same concentration but containing 5 or more than 5 C-atoms. Such seems to be caused by undissociated molecules of these acids.
(4) The already mentioned 3 kinds of the acids are graded as weak, strong, stronger in their bactericidal capacity when compared at the same pH-value, due to the difference of molecular concntration of each.
(5) Neither increase nor decrease in the number of carboxyl group in the acids in question is accompanied by any change in strength as bactericide.

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The author studied the relation between colour ratio, α of phenolphthalein, and its corresponding pH-value of the sea water as determined by B_RANDES⁽¹⁾ with P_ALITZSCH's buffer solution (boric acid-borax mixtures), and found that pH of it is a logarithmic function of α within a range 8.08-8.60 but not a linear one as obtained by B_RANDES.
My observations as given in Table 1 and Fig. 1 clearly show that a linear relation exists between logα and pH. Thus a colour ratio of pH 8.51 to pH 8.41, for instance, is tabulated to be 1:0.706, so that pH between these two values can be calculated from an equation,
α=(0.706)^1-x, where x denotes pH values to be added to the 1st decimal of pH 8.41. By such calculation figures denoting the relation between colour ratios and pH were obtained as listed in Table 2. The accuracy of this calculation method was tested by determining pH of P_ALITZSCH's buffer solutions containing a certain amount of borax solution,
(1) by the interpolation of the percentage of borax solution, …… pH₁
(2) by the calculation from their α-values according to Table 2, ……pH₂ and (3) by the interpolation of α-values assuming pH as a linear function of α₁……pH₃ (Table 3),
It is clearly seen in Table 3 that pH₂ is more accurate than pH₃. Colorimetric determinations were also carried out in order to obtain α-values of P_ALITZSCH'S buffer solutions containing the indicator, both at the higher and the lower temperature than 18°C. with the results given in Table 4, from which the temperature coefficient of phenolphthalein δ=0.012, (with deviation±0.001) was obtained. This value thoroughly corresponds to the rate of displacement of the halftransformation-point of the indicator due to temperature change as given by M_ICHAELIS⁽³⁾. Therefore, the value, δ=0.010, obtained by B_UCH⁽⁴⁾ seems to me to be too small.

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Methioninc, a sulfur containing amino acid which was discovered by M_UELLER (1921), has been found to be present in casein, egg-albumin, edestin, wool (?), gelatine (?), fibrin, protein of rice-bran, and brewery yeast, by several authors, such as M_UELLER (1923), O_DAKE (1925), D_U V_IGNEAUD and M_EYER (1931), and P_IRIE (1932). B_AERESTEIN (1932) determined the methylthiol group, characteristic of methionine, in several proteins, and assumed that methionine is widely distributed in many kinds of proteins. Recently, J_ACKSON and B_LOCK (1931, 1932), T. E. W_EICHSELBAUN, M. B. W_EICHSELRAUN and S_TEWART (1932) reported that the methionine, like cystine, is capable of unmistakably stimulating growth in albino rats subsisting on a basal diet poor in cystine.
Nevertheless, as far as we know, this amino acid has not yet been isolated in the proteins of feeding-stuffs such as muscle, silk-worm pupa, and soy-bean. The present author isolated methionine in crystalline form from these feeding-stuffs by Mueller's method, slightly modi-fied by O_DAKE, and identified it by elementary analysis both of the free amino acid and of its derivatives, namely copper salt and α-naphthyl-isocyanate, The yield of free methionine from the proteins of sardine muscle, whale muscle, silk-worm pupa, and soy-bean was 0.52, 0.37 0.43, and 0.08% respectively; that is, from moisture- and ash-free coagulable protein. Contrary to the result of O_DAKE. methionine was isolated with certainty, though in a small amount, from the soy-bean protein. Furthermore, it was found that the methionine fraction isolated from silk-worm pupa only was largely contaminated with glutamic acid. Although only a few kinds of protein were investigated in this present study, it might perhaps be presumed that metbionine would be generally wide-spread in proteins, especially in those of animal origin.

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The present paper is based on the daily records of the catch of the keddle nets (1) in the Nisimura fishing ground of Gotô in Nagasaki Prefecture and (2) in the Akaisizaki fishing ground on the east coast of Idu Peninsula. The former covers nine fishing seasons of “Buri” (Seriola quinqueradiata T. & S.) 1918 to 1926 inclusive, and the latter six seasons of the same, 1927 to 1932 inclusive.
The catches from the above mentioned two fishing areas consist of “Buri, ” “Iwasi” (Amblygaster melanosticta T. & S.), “Saba” (Scomber japonicus Houttuyn), “Maguro” (Thynnus thynnus (L.)), “Tobiuwo” (Cypsilurus agoo T. & S.) and “Sawara” (Scomberomus niphonius Cuvier and Valenciennes). In the present study, especial reference has been given to the analysis of fluctuation in the catch of “Buri, ” with the following results: -
(1) The size of the yearly catch of “Buri” in the Nisimura fishing ground is significantly correlated with the number of the catches of 1, 000 individuals and over a day (r=+0.82).
(2) The size of the yearly catch is mostly determined by the size of stock of the predominant year class which again depends on the conditions of life during the period of hatching which took place 4-6 years before the fishing. As to “Buri” fished on the Nisimura ground, a very large stock of it is obtained when the meteorological and hydrographical conditions are moderate (Fig. 3).
(3) The correlation between the time of first catch and the average water temperature in January is negligibly low (r=-0.16), and that between the time of the last catch and the average water temperature in March and April is not so high (r=+0.13 and r=+0.45). But the duration of the fishing period between the first and the last catches is longer than usual when the average water temperature in March is lower than that in January (r=+0.65), and when the rising of water temperature is slower than that in average year (Fig. 4).
(4) If the duration of the fishing season of “Buri” is represented by T days, the number of daily catches of “Buri” in T days by n', that of any other fishes by n" and the number of coincidences of both daily catches by p, then the probability of existence of any cause from which the catch of “Buri” is resulted to occur in coin cidence with (or against to) the catch of the other fish in question is numerically represented by the magnitude of the difference of P/T/(n'/T×n"/T) from 1. The data from the Akaisizaki fishing ground give that P/T/(n'/T×n"/T) is 1.0-1.3 for “Iwasi, ” 0.6-1.3 for “Maguro” and 0.5-1.0 for “Saba.”

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If a piece of net is set to spread over a square frame with a suitable dip and with the angles between the arms of knots properly adjusted at every point on the frame, a bowl-shaped net is obtained with no crease whatever. In the present paper the form of thus prepared net is surveyed and the forming of a bowl-shaped net with rectangular pieces of net only is given, with the results summarized as follows: -
(1) When two lines through the centre of the upper side of frame and parallel to two lateral sides of it respectively are chosen as x^- and y^- axes, the depth of the net, z, at any point (x, y) is represented by z/z₀=[1-4(x/a)²]^p[1-4(y/a)²]^q where z₀ is the depth of net at the centre of the upper side of frame, a the inner dimension of it, and p and q certain constants (1 (a) and 3 in the text figure).
(2) The bowl-shaped net of any size, therefore, can be formed with suitable rectangular pieces of net (2, 4 (a, b) and 5(a, b) in the text figure).

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