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

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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.