真珠袋の組織学的研究 2. 季節による真珠袋形成速度の差異

The speed in pearl-sac formation and the deposition of secretion product on the surface of the nucleus were histologically studied in the pearl oyster (Pinctada martensii). Four stages were described in the course of pearl-sac formation as follows : Stage 1. No particular change was found in the grafted mantle piece in this stage. Stage 2. The grafted mantle piece transformed into a crescent shape after development. Stage 3. The epithelial cells of the pearl-sac was found completely enclosed the nucleus. Stage 4. The deposition of secretion product was observed in the nucleus. Evidence was presented that water temperature evidently influenced the speed in pearl-sac formation, as given in Tables 1 and 2. In April, seven days after operation were required for Stage 3 in the most speedy example, and 17 days in all specimens so far examined. In August, Stage 3 reached 3 days after operation in the most speedy sample and 12 days in all specimens under observation.