1 0 0 0 OA 臺灣産淡水魚の一新種 : トゲウナギ
1 0 0 0 OA マガモ雌の所謂「雄化」4例
In Japan there have been collected only four wild specimens of what we call the Female Mallard assuming the male plumage. Among these intersex specimens, no. 2 example which came from Teganuma, Chiba Prefecture, was studied by Dr.Yamashina ('48) and was found to have had its right and left ovaries turned into testes. Concerning the remaining examples the same phenomena have been seen in the old females, such as the Mandarin Duck, the Teal and the Pintail, which must have been brought about by the shrinkage or some other disorder of their ovaries. Bluba ossea, an organ belonging to trachea, peculiar to the male duck, does not exist in these intersex specimens and proved not te be affected by means of sex hormone.
1 0 0 0 濠洲の「オポッサム」か : 活動寫眞の動物
1 0 0 0 OA 日本産倍足類及び脣足類の分類學的研究 : 4.ババヤスデ科の1新種と1新亞種
1.Rhysodesmus serrulatus n. sp. (Leptodesmidae) Lange ca. 27mm, Breite 5mm. Farbe gelblichbraun in Alkohol. Alle Metazoniten glatt und am Hinterrand findet man halbmondformige braunliche Wappen. Hinterecke des Seitenflugels vom etwa 5. Segment an Zahnartig nach hinten vortretnd, Vorder-und Hinterrander etwa vom 5. Seitenflugel an viele winzige Sagezahnchen vorhanden. Beim ♂ ; Sternit des 4. Beinpaares mit 2 keuleformigen Fortsatze und Sternit des 6. Beinpaares zewei niedrig nach vorn gerichtete Hocker vorhanden. Vom 7. Segment an weiter, befindet sich dornartige Kegel am Ende der Ventralseite von Prafemur des Beines. Gonopoden: Hufte oval, mit Huftstab, und neben ihm mehrere Borsten. Acropodit gerade, breit, und am Ende Plotzlich verschmalert, wo sich auch ein Zahnchen befindet. Prafemoralfortsatz kurzer als das Acropodit, und noch endwarts allmahlich verschmalert, einfach und an dem Grund glbt es kleinen Zahnfortsatz. Fundort: Kitayama-Kyo (Kii). 2.Rhysodesmus semicircularis hosidei n. subsp. Lange ca. 53mm, Breite 9mm. Metazonite dunkelgrun. Die Hinterecke vom 6.-9. Segment an zahnartig nach hinten vortretend, caudalwarts immer merklich. Metazoniten glatt und die vordere Halfte der ca. 5.-15. Metazoniten erhoht sich etwas. Sterniten sind dem R. semicircularis Takakuwa ahnlich. Prafemur bei ♂, ungefahr vom Siebenten weiterhin, besitzt ventral am Ende einen Dorn. Gonopoden sind dem R. semicircularis ahnlich, aber doch Acropodit dieser Unterart in der Mitte rechtwinkelich gebogen, wo sich auch ein Zahnfortsatz befindet, und wieder am Ende stark gebogen. Fundort: Kasa-Yama (Yamaguti-Ken).
1 0 0 0 OA 臺灣産淡水魚の分布を論じ併せて臺灣と附近各地との地理的關係に及ぶ
1 0 0 0 OA 日本産普通多足類の後胚発生 : X ヤケヤスデの生活史
The life history of Oxidus gracilis was observed at Niihama district (Ehime Prefecture, Japan) during the year 1959 and 1961. The results were as follows: 1. The animals pass through seven larval stadia and sexual maturity occurs in the eighth stadium. Sex differentiation takes place in the larvae of the fourth stadium. Male animals develop a pair of very minute gonopod-bud appears at the position where the eighth legs had grown in the former stadia. The gonopod-bud scarcely grows during the stadia from the fifth to the seventh. However, it changes abruptly to a pair of complete gonopods at the eighth stadium. 2. The animals may be divided into two strains according to their breeding season. a) Strain breeding in Spring: The adults begin to crawl out of hibernation in early spring, and lay eggs from April to May. The larvae of this strain become adult at the end of November and then hibernate. b) Strain breeding in Autumn: The animals hibernate at various larval stadia as the fifth, the sixth or the seventh, and become mature in the early summer of the nest year, and lay eggs in autumn.
1 0 0 0 OA 相州三浦三崎近傍ノ隱鰓うみうし科
1 0 0 0 擇捉島のハツカネズミに就て
1 0 0 0 擇捉島の鼠禍に就いて
1 0 0 0 OA 擇捉島のハツカネズミに就て
1 0 0 0 OA 擇捉島の鼠禍に就いて
1 0 0 0 OA 兎ノ解剖案内 : 前々號ノ續キ
1 0 0 0 OA 兎ノ解剖案内(二一頁ノ續キ)
1 0 0 0 渦虫および両生類幼生の尾の再生軸についての実験的観察
- 著者
- 手代木 渉 志田 孝夫
- 出版者
- 日本動物学会
- 雑誌
- 動物学雑誌 (ISSN:00445118)
- 巻号頁・発行日
- vol.77, no.11, pp.350-358, 1968-11
It is well known that in the amphibian tail the main axis of regeneration blastema is at the right angle with the cut-surface (Barfurth, 1923). The same view has been held by many investigators who worked with various animals. For supporting this view, the cellular materials concerned in regeneration must be produced uniformly from the cut-surface, as stated by E. Korschelt (1927) and Yo. K. Okada (1950). However, this did not hold in planarians, since the rate of production of new tissue at the cut-surfaces differs along the longitudinal or the lateral axes of the body. The rate of regeneration in the amphibian tail was exactly the same to that of planarians. When the planarian or amphibian tail was sectioned obliquely, the axis of blastema was not always at the right angle with the cut-surface. It has been conclusively shown in the planarian and amphibian tail that as the acute angle between cut-surface and the main axis of the body (section angle) approaches the right angle, the acute angle of blastema-axis to the main axis of the body (regeneration angle) falls to zero, while, the regeneration angle becomes at the right angle as the section angle approaches zero. This can be mainly explained by differences in the rate of regeneration of new tissue along the cut-surface of the oblique section.