On the Male Genito‐Urinary Organs of the Lepidosiren and Protopterus

Summary The more important features in the morphology of the male urogenital system of Lepitlosiren and Protopterus may be summarized as follows:— 1 The testis is very much elongated and is divisible into an anterior formative and n posterior vesicular and conducting region. 2 The posterior part of the vesicular region is connected with the tubules of the hind end of the mesonephros, which serve for the passage of the genital products. 3 In Protopterus the testis is connected with the kidney only at its extreme tip; in Lepidosiren there is a stories of about half a dozen segmentally arranged vasa efferentia which open into Malpighinn capsules. 4 In Protopterus the hind genital region of the kidneys is clearly marked off from the rest, and in this region the kidneys are fused across the middle line; in Lepidosiren there is only a slight attempt at this differentiation, and the kidneys of the two sides are posteriorly, as elsewhere, quite distinct. 5 The Wolffian ducts open in the adult inale by a common (Protopterus) or by two separate (Lepidosiren) papillae into the distal portion of the cloacal caecum, which is morphologically a urogenital sinus formed in ontogeny as a dilatntion of the fused, but originally separate, posterior portions of the Wolffian ducts.