. Buccinum : (the whelk). Buccinidae. 53 external surface of the sac at this point forms a perfect circle in transverse sections (Text-fig. 5). The cells of the lateral and basal walls of this circular sheath are of medium length. The cells of the dorsal wall are of extraordinary size and extend down into the cavity, forming a deep ridge, which extends for some distance from the blind end. This odontoblast ridge lies, of course, in the gutter formed by the radula. Thus one sees that the cells of the lateral and ventral walls are directed towards the basal ventral plate of the radula, whilst th
. Buccinum : (the whelk). Buccinidae. 53 external surface of the sac at this point forms a perfect circle in transverse sections (Text-fig. 5). The cells of the lateral and basal walls of this circular sheath are of medium length. The cells of the dorsal wall are of extraordinary size and extend down into the cavity, forming a deep ridge, which extends for some distance from the blind end. This odontoblast ridge lies, of course, in the gutter formed by the radula. Thus one sees that the cells of the lateral and ventral walls are directed towards the basal ventral plate of the radula, whilst the dorsal ridge cells are directed towards the teeth, both median and Fig. 5. As one passes towards the pharynx the depth of all the cells decreases, the dorsal ridge passes away and gradually the ordinary epithelial type is reached continuous with the epithelium of the pharynx. The nuclei of the odontoblast cells are oval, more or less elongated and contain numerous small granules. The most characteristic feature of the odontoblast, how- ever, is the free end of the cell, The secretion leaves it. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Dakin, William J. (William John), 1883-1950. London : Williams & Norgate
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1912
