著者
吉倉 真
出版者
社団法人日本動物学会
雑誌
動物学雑誌 (ISSN:00445118)
巻号頁・発行日
vol.79, no.11, 1970-12-15
著者
吉倉 真 城田 五郎 近藤 照義
出版者
Arachnological Society of Japan
雑誌
Acta Arachnologica (ISSN:00015202)
巻号頁・発行日
vol.27, pp.199-208, 1977
被引用文献数
1

1. 産卵後一両日中にウヅキコモリグモの持っている卵嚢を取り除いたら, 3週間ほどで再び産卵した. 初回の産卵数は平均約50個, 次回のそれは約33個であった.<br>2. 卵嚢保持個体における肥大卵母細胞の大きさは, 産卵後約4週間で直径約184μに達したものもあったが, 排卵したものはなかった. 産卵後一両日中に卵嚢を除去したものでは, 産卵後約4週間で肥大卵母細胞は直径約476μに達したものがあり, 直径450μ以上のものは排卵されていた.<br>3. 卵核胞は卵細胞の成長とともに大きくなる. 直径約40μの卵細胞において直径約33μであるが, 排卵までに直径約67μに達する.<br>4. 卵黄核も卵細胞の成長とともにある程度大きくなる. 卵細胞の直径70-90μで, その直径平均約23μであるが, それ以後排卵までその大きさにとどまる.<br>5. 卵黄粒は卵細胞の直径約150μ以上で形成され, 卵細胞の成長とともに大きさを増す. 排卵時, 最大のものの直径約35μ, 産出卵において最大のものの直径約56μであった.<br>6. 卵巣には初回産卵後, なお平均150個ほどの卵緒を有する卵細胞が残されている. 卵嚢が除去されると, それらのうちあるものが急速に成長し成熟する.<br>7. 退化卵細胞は産卵直後には十数個あるも, 次第に吸収され, 3-4週間後にはほとんどなくなる.
著者
吉倉 真
出版者
社団法人日本動物学会
雑誌
動物学雑誌 (ISSN:00445118)
巻号頁・発行日
vol.72, no.1, pp.13-16, 1963-01-15

The present study was undertaken with the object of determining whetehr the hypopysis has some connection with sex reversal in amphibians. Hypophysectomized or thyroidectomized frog larvae (Rana japonica) were treated with estrone (1mg/1) from 105 days of age for 45 days and thereafter maintained without estrone up to 225 days of age. In both groups of animals ovaries were not affected by estrone, but the testes, in most cases, were feminized (Figs. 1, 2). The hypophysis therefore had no connection with gonad feminization. After the treatment was stopped, feminized gonads of thyroidectomized larvae were restored to the testes, all of the ovocytes were destroyed, and the luteal-like bodies were formed (Fig. 3). On the other hand, feminized gonads of hypophysectomized larvae seemed to have evolved into the ovaries (Fig. 4). It seems probable that when the hormonal treatment is stopped, the hypophysis controls the developmental fate of the gonad feminized by the action of estrone.
著者
吉倉 真
出版者
社団法人日本動物学会
雑誌
動物学雑誌 (ISSN:00445118)
巻号頁・発行日
vol.76, no.11, pp.394-395, 1967-12-15
著者
吉倉 真
出版者
Arachnological Society of Japan
雑誌
Acta Arachnologica (ISSN:00015202)
巻号頁・発行日
vol.17, no.2, pp.19-24, 1961
被引用文献数
8

On July 12 and 13, 1953, the writer collected three females of <i>Typopeltis stim-psonii</i> together with their egg-sacs at Ushibuka in Amakusa, Kyushu. The embry-onic development of this species was very similar to that of <i>Thelyphonus caudatus.</i> When the eggs were collected (presumedly about two weeks after oviposition) the germ disk formation was already advanced. Two days after the germ disk for. mation the abdominal process, which was identified by SCHIMKEWITSCH (1906) as primitive cumulus, appeared near the margin of the germ disk (Figs. 1, 2). Then the germ disk was transformed into a germ band, which was segmented by cros-sing of transverse grooves and the cephalic lobe, cheliceral segment, palpal segment, and four leg segments were formed (Fig. 3). The abdominal process cut out successively the abdominal segments forward and by this teloblastic growth the abdominal portion grew in length (Figs. 4-7). No abdominal appendages appeared at any stage. The lateral organs appeared within eight days after the germ disk formation (Fig. 5). Near the hatching the egg membranes were perfora. ted by the egg-teeth which developed at the base of the palps and of the legs (Fig. 8). By moving of the embryo air was drawn through the incisions made by the egg-teeth into the space between the embryo and the egg membrane. Hatching and the first ecdysis occurred simultaneously by the 18th day after the formation of the germ disk.
著者
吉倉 真
出版者
熊本大学
雑誌
Calanus : 合津臨海実験所報 (ISSN:02886243)
巻号頁・発行日
vol.1, pp.18-23, 1968-05-20
著者
吉倉 真
出版者
社団法人日本動物学会
雑誌
動物学雑誌 (ISSN:00445118)
巻号頁・発行日
vol.64, no.7, pp.207-210, 1955-07-15

Ovotestes found in a female intersex specimen of Rana limnocharis were reported. 1. In both gonads the ovarian tissue is pathological: all ova are degenerating, theca and connective tissue are hypertrophic and fibrous, and the presence of polygonal masses of pigment is remarkable. 2. Islets of testicular tissue are scattered on the surface of both gonads. A testicular nodule lies at the anterior end of the right gonad. Vasa efferentia are not present. The spermatogenesis is normal. 3. Oviducts are well-developed. Seminal vesicles are not present. Secondary male sexual characters such as nuptial color, thumb pads, protruded larynx and vocal sacs are clearly recognized.