The spermatheca in the flour beetle (tribolium castaneum herbst)1

TLDR: A study of the serial sections reveals that the organ of the Tribolium, castaneulr I-Herbst is a blunt, apical, anterior swelling of the vagina which is totally unrecog nizable from outside.

Abstract: The( histology of the spermatheca of the Tenebrionid beetles has been very poorly studied. The structure of the spermatheca of Triboliu?, castaetur, IIHerbst differs greatly from the Coleop teran spermath ece described by previous authors (see Snodgrass, 1935; In mls, 1934). It is characterized by being unrecognizable in gross anatomcial dissection. The descriptive terms used in this paper are those employed by Snodgrass (1935). IATIRIALS AND M!IETHODS Adult females of Triboliinl castanJeum Herbst were fixed in Mukerji's fluid (Miukerji, 1937; Sinha, 1953, in press) and serial sections of the entire body, 8 micra in thickness, were made in transverse and longitudinal planes. The technique employed for sectioning the sclerotized beetles was that of Mukerji with the author's modification. Some dissections of the organ were also made in normal saline solution and later sectioned by the ordi nary, paraffin method. Sets of the serial sections of tlhe insects were stained in Mallory's triple stainl and Delafield's lemlatoxy li1 and Eosin, whereas the sets from the dissected organs were stained only in'the latter. DESCRIPTION The spermatheca of the Tribolium, castaneulr I-Herbst is a blunt, apical, anterior swelling of the vagina:t which is totally unrecog nizable from outside. It is 0.08 nmn. long and 0.1.3 mnm. in diam eter and is located 0.13 m11n. above the juncfion of the fifth and the sixth abdominal sterla (third and fourth visible sterna) in natural position. A study of the serial sections reveals that the organ is a rectangulatr mImus:cular chamber iomposcd- of four long