Spermatogenesis in Lumbricus terrestris L., Müll.

Abstract

WHILE the histology of spermatogenesis s.str., that is, the maturation of the spermatids to form ripe spermatozoa in Lumbricus terrestris L., is known in detail, explanations of the orientation of the developing spermatid remain somewhat obscure. The only complete and easily available information is contained in the general text-book of Borradaile¹, where diagrams show the ‘tail’ of the sperm arising at the cytoplasmic vesicle at the periphery of the mirula and remaining in this position during its subsequent elongation away from the cytophore. The cytoplaemic vesicle and the cytophore are shown in Fig. 1 (c.v., cph.). The account of Hesse² interprets the orientation of the spermatid in the same way as Borradaile, stating that the acrosome or ‘head’ end arises from the cytoplasmic pedicle which is directed towards the centre of the morula (Fig. 1, c.p.). Depdolla³, however, explains the orientation in the reverse way and regards the cytoplasmic vesicle as representing the acrosome or ‘head’ end of the sperm, and states that the ‘tail’ develops from the cytoplasmic pedicle. More recent work by Chatton and Tuzet⁴, who made a very detailed histological examination, confirms this view, though no figures are given in their work of the final relationship of the ripe spermatozoa to the cytophore.