Mateeial for the Study of Ruminants. 



33 



from Gobus defassa. As has been stated above I am inclined to think 

 that such a development of the penis as this one is the primitive one, 

 at least among the Cavicornia, and aberrant structures of this organ I 

 regard as being due to a secondary transformation usually in connec- 

 tion with a reduction in a more or less high degree, of the urethral 

 prolongation. In the members of Cervicornia investigated by Garkod 

 |1. c.) the penis end seems to differ widely from this type, being sym- 

 metrical, although otherw ise varying in shape. I Jut as Moschus and 

 Giraffa in this respect belong to what Garrod calls the »ovine» type, 

 it is probable that the condition found in the Cervicornia also is due 

 to a secondary reduction. This becomes the more probable when a 

 comparison is made with the Tragulina which often are regarded as 

 the most ancient among the Selenodontia. The specimen of Tragulus, 

 which I have had the opportunity to dissect, was not very well pre- 

 served, but the following observations could, nevertheless, be made. 

 There are to be distinguished at the distal end of the penis a cushion- 

 like organ and a terminal tapering portion. The former which, no 

 doubt, may he homologised with the cushion found on the penis of the 

 Ruminants enumerated above has. however, a somewhat different si- 

 tuation although its main part lies on the upper side of the organ as 

 usual. It extends along that side of the penis end. and tapers in a 

 forward direction. Posteriorly it is thicker, and its posterior end being 

 to some extent free, is recurved on itself and tits in into a groove on 

 the left side between the middle portion of the cushion and the penis 

 itself as is seen in the figure (fig. 20). The tapering portion includes 

 the urethra and is homologous with the more or less filiform urethral 

 prolongation of the above quoted Ruminants. The difference lies only 

 therein that it is more spirally twisted than the same organ of the 

 typical Ruminants and less strongly tapering than in (he »ovine» type 

 of Garrod. In Tragulus this urethral prolongation, to use the same 

 word as has been used above, at the end of the penis turns sharply 

 upwards on the left side. When it has come almost to a level with 

 the next posterior portion of the penis with the above mentioned cushion 

 it curves forwards and downwards again on the right side. Then it 

 ascends for the second time on the left side, but much less abruptly 

 and in a forward-sloping direction. The extreme tip is finally some- 

 what twisted, although its main direction is straight. The penis-end of 

 the Tragulus is accordingly shaped like a cork-screw. But in this re- 

 Nova Acta Reg. Soc. Sc. Ups. Ser. III. Impr. 24 ,' 7 1903. 5 



