18 BINAE LONNBERG, ANATOMICAL NOTES ON EAST AFRICAN MAMMALS. 



of 'papilla urethfalis which, however, rests in a groove on the lower side of the organ. 

 The reduction of processus urethralis is thus complete, but if it is assumed that a 

 similar reduction would take place in an organ shaped like that of a Gazelle (e. g. 

 O. rufina as figured by the present writer^) the result would be exactly such as now 

 has been described and figured (PI. 1, Fig. 8) for the Gerenuk. Although the penis- 

 end of the Gazelles and the Gerenuk at the first look appear to differ, this difference 

 is not at all fundamental, nor does it speak against the affinity of these animals. 



Such a shape of the male organ as that found in the Impala might also as a 

 result of reduction and simplification easily be derived from the type exhibited by 

 the Gazelles. This organ does accordingly not support Pocock's view that the Impala 

 should form a separate subfamily * of its own which the author quoted places between 

 Oervicaprince and Tragelaphince. It is readily admitted that a characteristic resulting 

 from reduction is no strong proof of relationship, but a comparison of the male organ 

 of the Impala with that of a Waterbuck or a Bushbuck on one hand, and with that 

 of a Gazelle on the other wiU plainly show that while a derivation from the latter 

 is quite easy to understand, a derivation from the Waterbuck is difficult and from 

 a Bushbuck hardly possible. 



From the subfamily Hippotragince already Garrod has described the male organ 

 of one of its representatives viz. Addax. The corresponding organ of a specimen of 

 Oryx beisa annectens obtained by the present author is very similar. The organ is 

 compressed from the sides and tapers somewhat in front (PL I, Fig. 9). The spiral 

 twisting is very pronounced. The urethral portion which is thick, 5 — 6 mm. in dia- 

 meter ascends from the lower side obliquely forward to the upper on the left side. 

 It is sunk in a corresponding groove to which it is attached until it reaches the upper 

 surface. It continues then, bending over towards the right side, still resting in the 

 groove but free, and extends forward beyond the tip of the other portion of the 

 penis which is formed by the cushion. The latter is on the left side seen in front of 

 the ascending urethral portion. The distal free part of the urethral portion tapers 

 gradually to its free end, but it does not become filiform, measuring as a minimum 

 a little less than 3 mm. at the orifice. The distance from the extreme tip of the 

 cushion below the free urethral portion and to the orifice of the latter is about 11—12 

 mm. The type of male organ found in Hippotragince as represented by Addax and 

 Hippotragus is thus, as can be judged from this, more primitive and less reduced from 

 the original Traguline, resp. Suine type than in other Cavicornia. 



Before our knowledge about the male organ of the Ruminantia comprised as 

 many different species as now, it has been suggested that there should perhaps be 

 some correlation between the size and bulk of the animal, and the shape of its penis. 

 Against such a supposition the present author has pointed out (1909) that even in 

 quite small antelopes like Nesotragus the shape of this organ can be of » bovine » 

 type. The presence of a penis type like that described above in such a big antelope 

 as Oryx gives a further proof that no such correlation exists. 



^ Nova Acta Reg. Soc. Sc. Upsala 1903. PI. 1, Fig. 3. 

 ^ Proc. Zool. Soc. 1900, p. 918. 



