The tongue in Wallago attu and Gadusia chapra is conspicuous while in Catla catla and Barbus stigma it is rudimentary. Both the mucous cells and taste buds occur in the mucosa of the tongue of fishes undertaken for study;. with the only difference in the inten sity of taste buds which are more in the tongue of Catla catla and Barbus stigma.
It may be emphasized that further work is necessary on the histology of the tongue particularly with a view to understanding its musculature.

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Chromis notatus (TEMMINCK et SCHLEGEL) is a common pomacentrid fish of southern Japan.
The author carried out the artificial insemination of thisfish on July 18, 1957, at Ushima, in Hikari City, Yamaguchi Prefercture, and reared the hatched larvae for about three days.
The spawning season seems to extend from early July to early September in the vicinity of Hikari City.
The egg is elliptical in shape, with a bundle of tendrils on one end, measuring 0.55-0.60mm in the short axis and 0.74-0.78mm in the long axis. The yolk is colorless with an alveolar structure containing a single oil-globule, measuring 0.21-0.22mm in diameter. The hatching took placein 58.5-70 hours at the water temperature 25.8-28.0°C (Text Figs. A-K).
Larva just hatched (L) is 2.21-2.40mm in total length. The mygtome number is 9+18-19=27-28 (vertebral number of this fish is 10+15=25). The melanophores are present on the head, on the yolk, on the intestine and along the ventral margin of the tail part. Several xanthophores are found aroulld the eyes and on the yolk surface. In three days after hatching the larva (M) reached 2.85mm and the yolk was entirely consumed.

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Sebastes pachycephalus nigricans (SCHMIDT) is a viviparous fish.
On December 8, 1956, a female parent fish kept in the aquarium for 2 days after being caught spawned larvae, at the Mekari Aquarium, in Moji City, Kyushu. The author reared these larvae for about one month in a glass jar, feeding with the brine shrimp nauplii.
Newiy spawned larvae (Fig. A), measuring 6.9-7.0mm in total length, had aremnant of yolk, and swam freely in the glass jar. The myotome number was 10+16-17=26-27. The pectoral fins were large prvided with 17-18 rays, which were densely pigmented with melanophores showing characteristic black appearance. The melanophores and small orange pigment cells were distributed on the head and trunk.
In 2 or 3 days after spawning the larva (B) attained 7.15mm in total length and the yolk was entirely consumed.
In 20 days after spawning the larva (C) measuring 9.75mm in total length reached the end of the post-larval stage. All the fins were well formed with a complete set of rays (D. XIII-12, A. III-6-7, V.I-5, P.16-18). The larva covered with melanophores and orange pigment cells from head to tail. The pectoral fins, ventral fins and the anterior part of dorsal fin were densely covered with melanophores. In addition to melanophores, the pectoral fins are densely distributed with orange pigment cells, effecting in a golden lustre.
The larvae lived for 28 days in the laboratory.

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The part six of this article contains detailed descriptions of life colors of ten species (nos. 87-96) of several genera found in Suruga Bay, Japan. The interesting species are as follows: Hoplostethus mediterraneus, Ostichthys japonicus, Nealotus tripes, etc.

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Paleatogobius uchidai TAKAGI is a small goby, some 35mm in total length, resembling to the gobies of the Genus Chaenogobius GILL: C. castanea (O'SHAuGHNESSY), C. heptacanthus (HILGENDORF), etc. (Fig. 1). It lives a bottom lif e on sandy mud bottom of estuaries in Kyushu, Japan (Fig. 2).
The sex-dimorphism is slightly observed in the form of genital papillae.The mature female fish are generally larger than the male. The black nuptial coloration appears in the mature female fish only on the ventral ahd anal fins, just as was reported in the gobies of the Genus Chaenogobius: C. castanea, C. heptacanthus, etc. (KINOSHITA, K. 1936, DÔTU, Y. 1954). The ripe ovary contained two groups of the eggs: the mature yellow one, 0.69-0.89 mm in egg-diameter, and the inmature translucent one, 0.14-0.34mm in diameter.The number of the mature ovarian eggs of one individualwas enumerated as 158-430 in eight specimens with the total legth 27-45 mm (Table 1). The ripe testis is thin and translucent band-form with a small appendant organ at its posterior end (WEISEL, G. F. 194 ). The spawning season seemed to extend from January to March in Fukuoka City and its vicinity. The spawning occurred in the ordinal habitat of the adult, as in the estuary of the River Kanakuzu in Fukuoka City. In the same place Chaenogobius castanea also spawned in same manner (Fig. 2; DÔTU, Y. 1954). The parent fish utilized vacant living holes of a kind of shrimp, Upogebia major DE HAAN, for its spawning room. Openings of the numerous holes were exposed all over the flat at ebb tide. The holes were short vertical ones, about one centimetre in diameter and about twenty centimetres long. The spawned eggs were deposited on the inner wall of the hole about five centimetres deep from the opening. The male parent fish was guarding the eggs in the hole until the eggs hatched out. The number of one brood was enumerated as 114-174 in five cases. The water-temperature at the spawning ground was 9.6-14.5°C in the spawning season. The fertilized egg is demersal and adhesive, with a large perivitelline space and a bundle of adhesive filaments at its basal end. The egg is club-shaped, 2.40 mm in long axis and 0.84 mm in short axis, with a shallow depression circling near the top (Fig. 3, Fig. 4). This egg resembles to that of C. castanea in shape, but smaller.
The newly hatched larva is 4.3mm in total length (Fig. 5 _A). The postlarvae under 10mm in total length were not yet collected. The postiarvae, 10-15mm in total length, were collected with drawing-nets in Fukuoka Bay from May to July (Fig. 5 _{B C}). These larvae supposedly live a swimming life in the bay. The last postlarvae, over 15 mm in total length, were found already entering into the bottom life at the estuary where the adult fish lived (Fig. 2; Fig. 5 _{D E}). The gut-contents of the postlarvae, supposedly carrying a swimming life, consisted chiefly of planktonic Copepods, whereas that of the adult consisted of worms, young fish, and organic detritus (Fig. 5 _F).
The examination of the size-frequency of the collected specimens, over 450 individuals, collected from Fukuoka City and its vicinity shows preliminary that this goby attalns 26-31 mm in total length, and becomes mature in a year; in two years it willattain 31-37mm. The largest specimen examined is a female fish, 52mm in total length.

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Girella punctata GRAY is a common shore fish in Japan, attaining some 500 mm when full grown.
The author operated artificial insemination of this fish on February 6, 1956, at Urashiri, Nobeoka City, Miyazaki Prefecture, Kyushu, and observed egg development and hatched larvae (Fig.1. a-i).
The egg is bouyant, transparent, colorless and spherical in shape, measuring 1.01-1.05mm in diameter with a single oil globule measuring 0.23-0.25mm in diameter.
The egg development is much the same as other pelagic fish eggs.
Hatching took place in 53-55 hours at the water temperature 16.5-17.2°C, and 60 hours at 11-20°C (mostly 14-17°C).
No pigment developed in the egg.
The newly hatched larva was 2.27-2.35mm in total length, the oil globule situated in the posterior part of the yolk. The myotome number is 11+16 or 10+17=27 (vertebral number of this fish is 10+15=25) (g).
In 1.5 days after hatching the larva attained 2.98-3.01mm in total length, and dendrite melanophores appeared on the yolk surface, and ventral side of the body.
In 3 days the yolk and oil globule was almost entirely consumed and the larva attained 3.58 mm in total length. The melanophores increased in size and number, and the new ones appeared on the dorsal side above the rectum and the posterior part of the tail. The myotome number is 8+18=26.

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The writer has further more enumerated twenty-two unrecorded species of fish with their brief descriptions, which are to be newly added into a list of fish of Niigata Prefecture, Sea of Japan.
Among these fish, there are one fresh water fish, twelve temperate or subtropical fish, and nine boreal bottom fish.

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In this paper the author has newly described on the thyroid gland of Japanese teleosts, mackerel, yellow skin tuna, Pacific marlin, Japanese parrot fish, cold porgy and smooth lump sucker. Moreover, the external morphology and histology of some Japanese teleosts have been discussed including the data of other fish.
1) The external morphology of thyroids of yellow skin tuna and Pacific marlin were closely similar to those of tuna and sail fish reported in the previous paper, respectively. The thyroids of these fish lied on the bifurcated regions of the 1st and 2nd afferent branchial arteries which derive from the ventral aorta, and Were the compact masses consisting of anterior and posterior lobes. A nearly identical shape of thyroid was observed in the glands of mackerel, frigate mackerel, dolphin (or dorado), yellow tail, etc.
2) The thyroids of Japanese parrot fish and cold porgy existed as a single mass and both of anterior and, posterior lobes were distinguished clearly. In smooth lump sucker the thyroid consisted of only a single mass. It has been considered that these matters are under the control of the condition of afferent bronchial arteries which derive from the ventral aorta.
3) The wet weight of thyroid mass per 1 kg of body weight ranged from 9. 00mg (minimum) of a mackerel to 52. 50mg (maximum) of a smooth lump sucker and represented 29.07mg as an average value of ten species of fish ; namely, tuna, sail fish, yellow tail, Hiramasa, mackerel, yellow skin tuna, Pacific marlin, Japanese parrot fish, cold porgy and smooth lump sucker.
4) Among six species of fish reported in this paper, only the thyroid of cold porgy showed a hyperfunctioning figure. On the other hand, the thyroids of remaining five species of fish appeared to be in the condition of norml activity. In some fish which have compact masses of thyroid, the state of their thyroid activity could not be decided only by their histological figures.

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The eggs of Wakin (goldfish) immediately after deposit (Exp.I) and the larval fish 10 days after hatching (Exp.II) were immersed in a solution containing 1/3, 000 of thiourea until the decolorizing period of the control fish. Also, the larvae 10 days after hatching were kept for only 45 days (Exp.III) in the same solution. The normal larvae 55 days after hatching were reared for 55 days in the thiourea solution. The effects of these treatments to the developing processes of goldfish larvae were observed and the following results were obtained.
1. The treatment of thiourea inhibits the growth of goldfish larvae remarkably; namely, increase of weight, length of body and head, depth and width of fish. The order of the delaying of growth rate are as follows Exp.II>Exp.I>Exp.IV>Exp.III>Control.
The body form of the treated fish is very poor and the considerable downward bending of caudal vertebra are observed, so that these fish do not represent common Huna-gata (crucian carp shape). In Exp.III, however, the body form regains almost that of the normal fish until the decolorizing period of control group, and the form of Exp.IV shows no particular change. Furthermore, in Exp.I the Mitu-o (tri-lobed tail) are produced in a high rate.
2. The ground coloration of treated larvae becomes yellowish brown gradually instead of Hunairo (iron color) of control fish. And as the deposition of guanin to the scales are suppressed, the treated fish become just like the goldfish in the condition of transparent scales.
The treatment of thiourea inhibits the decolorization of goldfish larvae. In Exp.III, however, their ground coloration returns to that of the normal fish gradually and these fish perform the decolorization. Moreover, in Exp.IV the coloration of decolored fish is yellowish orange, although the coloration of decolored. fish of the control group is clear orange.
3. The thyroid glands of Expts. I, I, and IV indicate the hyperfunctioning figures with hypertrophy and hyperplasia of epithelial cells and follicles. On the other hand, the thyroid of Exp.III recovers from the pathological condition and shows the hypofunctioning figures like the control fish.

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We tried a preliminary consideration of the newly mingling fishes in eel-culture pond. It is as follows:
Lateolaborax japonicus, Milio macrocephalus, Clupanodon punctatus, or Carassius auratus were estimated as fishes unfit for the culture. Such species as Liza haematocheila, hakuensis or Aplocheirus latipes were believed as mingling fishes fit for the culture, but these economic values may be questionable.
Therapon oxyrhynchus and T. jarbua were regarded to be of most excellent species as mingling fishes together with Mugil cephalus.

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I. The comparative analysis of the fiber distribution on the lateral-line of fish is made. And we can find the differentiation among them.
II. We discuss on the relation between the function of the lateral-line organs and the habits of the fish from the ecological stand point of view.
Results of our studies lend support to the view that the habit of the fish belonged to the three groups may depend upon the function of eac own hnerve.

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The behaviours of fish in response to the sound stimuli were observed by using the fire-work under the water and by striking the bottom of the cask as the source of sound. It is now made clear that the critical sound-intensity to affect the bahaviours of fish varies from one species to the next, and mackerel, (Scomber japonicus) and horse mackerel (Trachurus japonicus) are rather sensitive fish, but conger eels except Rhyncocymba nystromi nystromi are less sensitive.

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The chromosome of six species of the Gobiidae were investigated in male germ cells through spermatogenesis, with special regard to the chromosomal relationship in closely related species. The chromosome numbers of the species under study and chromosomal formulae are summarized in Table 1.
The spermatogonial complements of the studied species contain small-sized chromosomes as referred to as m-chromosomes, with the exception of Gobius simils. Each species is characterized by possessing a definite number of such m-chromosomes.
The reduction of the chromosome number which occur beween Gobius simils and Gobius abei, and between Chaenogobius urotaenia and Chaenogobius isaza seems to be due to the disappearance of the m-chromosomes.

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1) In this paper is reported the reciprocal crosses between the mud loach, Misgurnus anguillicaudatus (CANTOR) and the 2 different species, Barbatula toni oreas (JORDAN, et FOWLER), Lefua nikkonis (JORDAN et FOWLER), all belonging to defferent genera.
2) In these intergeneric crossings the time for hatching was always more delayed than in the normal crossings. The eggs thus fertilized had more death-rate than in normal eggs, especially in those from the gastrula to the formation of embryo body.
3) The ratio of the hatched eggs from M.a. _??_×B.t.o._??_, from B.t.o. _??_×M.a. _??_, and from M.a. _??_×L.n. _??_ was 20%, 30% and 60% respectively, L.n. _??_×M.a._??_ being failed by a technical failure. In the larvae hatched from M., a. _??_×B.t.o _??_ and B.t.o _??_×M. a. _??_, nearly all of them became abnormal such as curvedin the body, and died in 2-3 days after the hatching. A few normal ones survived for 10-13days. On the colltrary, most of the larvae hatched from M.a._??_×L.n._??_ were nearly normal in form, but they did not take foods and died in 14-16 days. Thus the larvae produced from these intergeneric crossing died all at early stage. These fish had the paternal characters as to the developmental course of gill and chromatophores, and the number of myotomes.
4) On microscopical observations on the larvae from M.a. _??_×L.n. _??_, the development of the circulatgry system was found to be arrested in 2-3 days after hatching, and in these fish an edima appeared between the yolk and the epidermis, and the viscera, muscles and connective tissues were loose in structure even in 6-7 days after hatching.
5) From the result of this research, it can be concluded that Misgurnus anguillicaudatus (CANTOR) stands in more intimate relation with Lefua nikkonis (JORDAN et FOWLER) rather than Barbatula toni oreas (JORDAN et FOWLER).

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1) in this research it has been confirmed that the ovulation of female loaches was accelerated by injection of the hypohyses.
2) The female loaches most adequated for the purpose are those with softly swelled abdomen and pectoral fins and the anus around which were congested.
3) After the implantation of 3-4 pieces of hypohyses in each female, the recipients were kept in water from 28°C to 30°C.
4) The loaches artificially spawned in 14-15 hours after the injection produced mature eggs.
5) The ovaries of immature loaches were accelrated to develop by twice in jections. Some of them spawned mature eggs, but most of them developed abnormaliy and were died before hatching.

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The breeding season of the loach, Barbatula toni oreas (JORDAN et FOWLER), begins from the begining of April and lasts to the end of May in Asahigawa region. The females just finished spawning were captured toward sunset, in sewers and irrigating canals rather than in rivers. The eggs were fertilized by artificial insemination and hatched larvae were reared in water, 13°-16°C for approximately 10 days. The egg is deep yellow and transparent, spherical in shape, demersal and strongly adhesive in nature, measuring 1.26 mm in diameter. The process of development is in the ordinary way as in the teleosts. In 2 hours and 30 minutes it completed the first division, and reached morula stage, in 5 hours and 30 minutes, and set in the formation of the embryonal body. In 95 hours Kupffer's vesicle disappeared and the heart was formed. In 115 hours the eye balls were provided with melanophores and embryonal body began to move and myotomes increased to 34 in number. The hatching took place at about 168 hours.
The newly hatched larva was 4.0 mm in total length, with 23+16=39 myotomes. No _melanophores were deposited in the body except the eyes. Within 3 days after hatching the larva began to swim freely and the stellate melanophores appeared in the head. Four days after that the yolk was all absorbed and the larva began to eat foods. During the development these larvae had no external gills as was in those of Misgurnus anguillicudatus.

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