Electron microscope observations have been made by means of the replica method on growth processes of calcite crystals of the nacreous layer of the shell of the oyster, Crassostrea virginica. Layer formation is initiated by the secretion of a conchiolin matrix and the deposition of rounded crystal seeds on or in this material. In some areas crystal seeds are elongate and within a given area show a similar orientation, probably due to slower deposition. The seeds appear to increase in size by dendritic growth, and smaller seeds become incorporated into larger ones which come into contact to form a single layer. With further growth, crystals overlap, forming a step-like arrangement. The direction of growth is frequently different in neighboring regions. Crystal seeds deposited on crystal surfaces are usually elongate and oriented. Well developed crystals have a tabular idiomorphic form and are parallel in their growth. Rounded and irregular crystals were also observed. The crystals show reticular structure with units of the order of 100 A and striations corresponding with the rhombohedral axes of the crystals. The role of the mantle is discussed in relation to the growth patterns of crystals and shell structure.
Article|
May 25 1958
Studies on Shell Formation : VIII. Electron Microscopy of Crystal Growth of the Nacreous Layer of the Oyster Crassostrea virginica
Norimitsu Watabe,
Norimitsu Watabe
From the Department of Zoology, and the Department of Experimental Surgery, Duke University, Durham, North Carolina, and the Duke University Marine Laboratory, Beaufort, North Carolina
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D. Gordon Sharp,
D. Gordon Sharp
From the Department of Zoology, and the Department of Experimental Surgery, Duke University, Durham, North Carolina, and the Duke University Marine Laboratory, Beaufort, North Carolina
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Karl M. Wilbur
Karl M. Wilbur
From the Department of Zoology, and the Department of Experimental Surgery, Duke University, Durham, North Carolina, and the Duke University Marine Laboratory, Beaufort, North Carolina
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Norimitsu Watabe
From the Department of Zoology, and the Department of Experimental Surgery, Duke University, Durham, North Carolina, and the Duke University Marine Laboratory, Beaufort, North Carolina
D. Gordon Sharp
From the Department of Zoology, and the Department of Experimental Surgery, Duke University, Durham, North Carolina, and the Duke University Marine Laboratory, Beaufort, North Carolina
Karl M. Wilbur
From the Department of Zoology, and the Department of Experimental Surgery, Duke University, Durham, North Carolina, and the Duke University Marine Laboratory, Beaufort, North Carolina
Received:
November 01 1957
Copyright, 1958, by The Rockefeller Institute
1958
J Biophys and Biochem Cytol (1958) 4 (3): 281–286.
Article history
Received:
November 01 1957
Citation
Norimitsu Watabe, D. Gordon Sharp, Karl M. Wilbur; Studies on Shell Formation : VIII. Electron Microscopy of Crystal Growth of the Nacreous Layer of the Oyster Crassostrea virginica . J Biophys and Biochem Cytol 25 May 1958; 4 (3): 281–286. doi: https://doi.org/10.1083/jcb.4.3.281
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