VISCERA OF AN OKAPI. 



195 



The two tributary ducts unite in the Giraffe (the junction was 

 destroyed in the Okapi) close in front of the gland to form a 

 single Wharton's duct (text-fig. 3, Wd.), and there is no reason to 

 think that the separate lobule drained by the anterior tributary 

 is anything but a part of the submaxillary gland, for the retro- 

 lingual gland, which at first sight it might be supposed to be, is 

 represented in Ruminants, including the Okapi and Giraffe, by 

 a mass of gland-tissue surrounding the anterior extremity of 

 Wharton's duct close behind the symphysis of the jaw, between 

 the origin of the genioglossus muscle and the sublingual mucous 

 membrane (text-figs, 1, 3, rl.gl.). 



The sublingual gland calls for no comment. The parotid gland 

 had been removed with the skin. 



Text-figure 10. 



Upper end of stylohyal of (A) Okapia and (B) Soemmering' s Gazelle. 



The Blood-vessels of the Tongue (text-figs. 11, 12, 13). 



In his description of the anatomy of the Giraffe, Owen * 

 mentions a peculiar plexiform arrangement of the veins close in 

 front of the body of the hyoid bone. In this position there is 

 generally among Ruminants a, large venous anastomosis uniting 

 the lingual veins of either side. This anastomosis was strongly 

 developed in the Giraffe's tongue (text-fig. 11, v. a.) dissected for 

 comparison with that of the Okapi, and in front of it, upon the 

 left side (text-fig. 11, v.pl.), there was some slight branching and 

 reunion of the veins, suggesting the plexus mentioned by Owen. 

 There was no indication of a plexus in the Okapi (text-fig. 12). 



Posteriorly, the lingual vein passes through the substance of 

 the submaxillary gland, and where it emerges again to the sur- 

 face receives the facial vein (text-fig, \,f.v.). At this spot lies a 

 very definite lymph-gland, which in the Giraffe lies embedded in 

 the substance of the salivary gland, and by its dark colour forms 

 a very striking object when the surface of the gland is exposed. 



* Owen, Trans. Zool. Soc. vol. ii. 1841, p. 223. 



