280 DR. C. F. SONNTAG ON THE ANATOMY 



posterior rows are close together. All are hemispherical, and 

 their surfaces are smooth or granular. 



The Conical Papillce. 

 The arrangement, distribution according to size, and course of 

 their points follow the usual type, and the interpapiliary dorsum 

 appears as narrow lines. 



The Lateral Organs (text-fig. 16 C). 

 The prominent lateral organs extend over the lateral borders 

 from the dorsum to the inferior surface. The primary sulci are 

 deep, and the laminse, which possess secondary sulci, appear as 

 small rods. Each organ is concave towards the lateral vallate 

 papilla of its own side, for the laminse run in different directions. 

 The lateral vallate papillce (l.v.t.) are level with the posterior 

 laminae. The anterior laminse run upwards and backwards, the 

 middle laminse are vertical, and the posterior laminse run upwards 

 and forwards. The limits of the organs are shown, in text- 

 figs. 16 A, /and B, /. Each organ is 1 cm. long. The right one 

 has 13 laminse and 14 sulci, and the left one has 13 laminse and 

 14 sulci. At the anterior end a small fold of mucosa is seen. 



The Frenal Lamella (text-fig. 16 B, g). 



The triangular lamella has a bifid apex. Its crenated edges 

 run postero-laterally as far as the middle of the lateral organs. 



The median ventral sulcus is shallow and wide, the frenum is of 

 moderate length, and the ventral 'papillary zone is narrow. 



Glands and Lymphoid Tissue (text-fig. 16 A, I). 



The whole of the dorsum, behind and at the sides of the 

 vallate triangle, is covered with white circular or oval areas 

 containing round or slit-like orifices. These glands increase in 

 size from before backwards, and their secretions keep the tongue 

 viscid. They are more developed than in the Cercopitheques, 

 Macaques, Mangabeys and Baboons. The viscidity of the tongue 

 remains for a long period, even in preserved specimens. 



These large lingual glands are accompanied by an enormous 

 development of the salivary glands (text-fig. 16 B, h <fc k). 



The lingual and salivary glands of the Langurs form a larger 

 glandular apparatus than in all other Primates. In the case of 

 the lingual glands ocular inspection and microscopic examination 

 must both be employed to estimate their area. 



The Physiology of the Ungual Glands and Stomach. 



To understand the significance of the great development of the 

 lingual and salivary glands, one must take into account the 

 nature of the diet, the presence or absence of cheek-pouches, the 

 degree of complication of the stomach, and the size of the caecum. 



The Langurs have no cheek-pouches, large lingual and salivary 

 glands, a complex stomach, and a caecum of moderate length. 

 They eat leaves almost entirely. 



