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RESEARCH PRODUCT

The ultrastructure of the thread-hairs on the cerci of the cockroach Periplaneta americana L.: The intermoult phase

subject

description

The structure of the thread-hairs on the cerci of the cockroach Periplaneta american during the intermoult phase has been investigated by scanning and transmission electron microscopy. The present study demonstrates that to each thread-hair belong one sensory cell, two glial cells, and three enveloping cells. The data indicate that: (a) the inner glial cells, which may have a trophic function, sends fingerlike processes into the cytoplasm of the senory cell body; (b) the internal enveloping cell forms the dendritic sheath; (c) the middle enveloping cell corresponds to the trichogen cell and the external enveloping cell to the tormogen cell; (d) the outer dendritic segment terminates in a canal (ecdysial canal) above the hair base; (e) a tubular body lies at the distal end of the outer dendritic segment; (f) below the base of the tubular body the outer dendritic segment is constricted by a thickening of the dendritic sheath, which might serve to prevent a downward movement of the tubular body during stimulation; and (g) apparently the oscilliation direction of each thread-hair is determined by the shape of the hair base.