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Material and Methods

Adult specimens of the slug Athoracophorus bitentaculatus were collected from the leaf bases of a flax plant (Phormium tenax) in Ngaio, Wellington, from March to September. The animals were narcotised in a relaxed state in mentholised water according to the method of Abdel-Malek (1951). The entire reproductive system was dissected free with the aid of a binocular microscope, fixed in Bouin's solution for three hours, placed in a saturated solution of lithium carbonate in 70% isopropanol for 1 hour, and stored in 70% isopropanol until required. After dehydration, the material was placed in chloroform overnight rather than in xylol, as it was found that clearing in xylol, even for periods as short as 30 minutes, rendered the tissues of the albumen gland very hard and brittle. The entire reproductive system was then embedded in 56°C —melting point paraffin wax and serially sectioned at 7 μm. Sections were stained in either Ehrlich's haematoxylin and alcoholic eosin, or in Masson's trichrome stain, or with PAS, using Delafield's haematoxylin as a nuclear stain.

To facilitate the construction of a sectional diagram of the reproductive system, every 6th section was photographed, and relevant portions of the photographs were traced to build up a composite picture.