OF THE TONGUES OF THE MAMMALIA. 



121 



Each fossa may contain one or more papillae (text- fig. 10, 

 nos. 5-9). When there are two, they appear as separate 

 cylinders, or as two halves of the same oval. Moreover, the 

 several cylinders may be the same or of different sizes. 



The papilla may be round, oval, or keeled, and its surface may 

 be smooth, polished, and glistening, or granular. When it is 

 granular, it may appear finely dotted, or covered with coarse 

 tubercles. Sometimes there is a central depression or umbilicus 

 (text-fig. 10, nos. 9-12). The granules may represent secondary 

 papillae. 



The vallum may slope and appear as a mound on which the 

 papillse ai'e set prominently, but that is not common ; it occurred 

 in the Indian Muntjac. It usually takes the form of a zone 

 round the papilla and fossa, and it may be smooth, furrowed, 

 lobulated, or covered with conical papillae. When it is lobulated, 

 the divisions may be round, oval, rhomboidal. There may be 

 two rows — an inner one of round, and an outer one of reniform 

 elements. 



Text-figure 11. 



l.L.C.P. 



\ 



The blood-vessels of the vallate papillary region of Ilacaciis rhesus. 



L.L.C.P. aiKl R.L.CP., right and left lateral papilla?; P.C.P., posterior vallate 



papilte. 



The tongue of the Common Badger exhibits an interesting 

 form of vallate papillary region. It is coloured brown, and the 

 papillee appear as if they are beneath the surface, and shine 

 through the mucous membrane, which looks as if it is composed of 

 transparent mosaics. 



The diJBferent forms of vallum are shown in text-fig. 10, 

 nos. 13-20. 



If the tongue is. removed soon after death, the blood-vessels 

 supplying the vallate papillary region may be seen injected with 

 blood. In the Rhesus and Common Macaque Monkeys, two 

 artei-ies pass forwards in the middle line, and, when they reach the 

 papillary region, they divide into two branches — a mesial and a 

 lateral one. The mesial branches pass between the posterior 

 papillae, and the lateral ones pass to the outer sides of their 

 corresponding papillse. whence they can be traced running out to 



