16 DR. C. F. S0NNTAG OX THE ANATOMY 



the centre of the anterior two-thirds of the dorsum, but, as their 

 points face in all directions, they appear tangled and without any 

 definite method of arrangement. In that central area, again, 

 fungiform papilhe are concealed by the conical forms. There is, 

 therefore, a similarity to the condition already described in the 

 Chimpanzee, and shown in text-fig. 1 A, but the papillae are more 

 diffused in the latter. 



The papillae belong to the filiform and cylindrical types, but 

 the former predominate, thereby giving the dorsum its shaggy 

 appearance. 



The base of the tongue is devoid of the long conical papillae 

 which are present in the other Anthropoids, and it resembles 

 that of Man in this respect. 



On the sides of the tongue they are in vertical chains, and on 

 the inferior surface they are in lines passing from without 

 inwards. 



In all situations, except on the central area of the dorsum 

 described above, the points are directed backwards. 



The Lateral Organs. 

 Boulart and Pilliet [2] state that the lateral organs have each 

 twelve laminae, but I found that the numbers of fissures and 

 ridges differ on the two sides as follows : — 



Right organ: Length 1*6 cm. Ridges 14. Sulci 15. 

 Left organ: Length 1*6 cm. Ridges 12. Sulci 13. 



The ridges run oblicjuely from below upwards, and they 

 diminish in size both forwards and backwards, but the organs 

 are continued by simple folds of the mucosa. 



The lateral organs end posteriorly on a level with the most 

 external vallate papillae. The greater part of each lies on the 

 dorsum as in the Gorilla, but some of the anterior laminae and 

 sulci project considerably on to the lateral borders of the tongue. 



Lymphoid and Glandular Tissue. 



The Orang-Outan agrees with Man and differs from all other 

 Anthropoids in the possession of the Apical Gland of JVuhn. 

 Mucous and serous glands occur as usual on the base of the 

 tongue, but there are no large follicles with central pits as in 

 Man and the Chimpanzee. 



On the inferior surface there are several small pits surrounded 

 by a raised zone (text-fig. 4 B), but histological examination alone 

 will reveal their true nature. I have been unable to study these 

 as my specimens have been preserved too long in formalin for 

 satisfactory histological work. 



The frenum lingum is well-marked, as in Man, the plicce 

 fimbriate, are of no greater development, and the /renal lamella 

 is as in the human tongue ; it is not a triangular process as 



