OCR Text |
Show 224 PROF. W. B. BENHAM ON AQUATIC [Nov. 3, of the ventral chaeta. A transverse section through the sperm-duct has all the appearance of a section across a nephridium : w e see, not an epithelium surrounding the lumen, but a perforated cell, with rarely more than one nucleus in the plane of the section, Text-fig. 23. VIII Plan of genital organs in Haplotaxis heterogyne, composed from study of entire w o r m and sections. The gonads are omitted on the right side in order to show the full course of the sperm-ducts, each of which leaves its funnel at its ventral edge; it has a course similar to that of a nephridium, and, like the latter, traverses a cord of cells. JVe1, the first nephridium; Ne?, the second; Ne.f., nephridial funnel; O.d., oviduct; O.s., ovisac ; Ov., ovary; Sp.d., sperm-duct; Sp.f., sperm-funnel; Sp.s., sperm-sac; Spth., spermatheca; t., testis. |