760 DR. C. F. SON^NTAG ON THE COMPARATIVE ANATOMY 



of vaiying degrees of obliquity behind that. The apical cluster 

 is large in the Simiidae and Cercopithecidae, but in all other 

 families the transverse rows extend far forwards at its expense. 

 In the majority of tongues with large apical clusters tliere are 

 many fungiform ])apilhe on the ventral papillary zone. 



It has been shown by Tuckerman that the fungiform pspillfe 

 of the apical cluster have many taste-buds. 



In some specimens of Anthropopiiliecus troglodytes there is a 

 row of prominent fungiform papillte occupying the mid-dorsal 

 line of the tongue and replacing the median dorsal sulcus. 



It is sometimes impossible to tell whether a pa.pilla at the 

 posterior part of the oral division of the dorsum is a large 

 fungiform or small vallate form, for fossa and vallum may be 

 indistinguishable even through a strong lens. Histological 

 examination is the only proof. The fungiform papillse may have 

 no taste-buds or these, if present, lie on the free upper surface of 

 the papilla ; in the vallate papillae, on the other hand, the taste- 

 buds never lie on the free upper surface of the papill;i., but are 

 deep down on one or both sides of the fossa. 



In some tongues there are more fungiform papilke than are 

 visible to the naked eye, for some are entirely concealed by 

 overhanging conical papillte (e. g. Antliropoiyithecus troglodytes). 



The fungiform papillae on the ventral zone may be thickly 

 clustered at the apex of the tongue and scanty further back, or 

 vice versa, and the examples, and the rows in which they a.re 

 arranged are close together or discrete. 



From the point of view of classification the most important 

 features are the size of the apical dorsal cluster and the presence 

 or absence of the fungiform papillae on the ventral papillary zone. 

 Although their presence or absence in the centre of the oral 

 part of the dorsum varies greatly, it is not a character of 

 sufficient distinctness to be of value for purposes of classification. 



The Conical Papilloi vary in size and arrangement in the 

 different families, and there are three types of the former : — 



1. The papillae on the pharyngeal part of the tongue ai-e 

 small : — Homo, Simia satyrtts. 



2. The papillae on the oral part of the tongue are compara- 

 tively small, but those on the pharyngeal part are large and 

 prominent: — Gorilla gorilla, AathropopitTiecus troglodytes, all 

 species of Hylohates, all species of Lemur, Chiromys onadagas- 

 cariensis, a,nd Tarsius spectrum. This type also occurs in some 

 lower Mammalia. 



3. The papilla? gradually increase in size from the apex of the 

 tongue back to the epiglottis : — Cercopithecidae, Cebidae, Hnpalidse, 

 Lorisidae, and Galagidae. This arrangement is also present in 

 Microcehus in which the vallate papillae form a triangle, so the 

 papillae are of value for distinguishing it from Lemur. 



The arrangement of the papillfe distinguishes most of the 

 Cebidae from all other families. In the latter they form a cluster 

 behind the apex and rows of varying degrees of obliquity behind 



