1883.] TONGUES OF THE MARSUPIALS. 613 



approach the organs as hi Halmaturus (ruuniug beneath the epi- 

 thelium of the general surface). The bulbs are found on the sides 

 of the furrows in about 7-10 tiers, extending right up to the lips of 

 the opening. Beneath the bulbs there is also the same delicate 

 subepithelial layer that exists in the circumvallate papillce ; there 

 is also the same dense mucosa with striated muscle-fibres ter- 

 minating in it. (This is a character of the whole organ, and the 

 possible significance suggested above is a result of its greater relative 

 predominance in that particular region.) 



C. The Fungiform PapillcB. — As described above, I include these 

 structures under the present head because of the existence of bulbs 

 in them ; but I believe that they are essentially tactile, and it has to 

 be proved that they are gustatory in any case. The bulbs are of 

 the same primitive type described in this position in Perameles. 

 The bulbs are evidently a very recent development in the fungiform 

 papillce of Marsupials. 



II. Mechanical and Tactile Structures. 



A. The Coronate Papillce. — Over much of the surface of the 

 organ there is no very distinct backward sweep of the secondary 

 papillae, but a very decided curve inwards and upwards, even carried 

 to the middle line. Anteriorly the backward curve is followed. 

 The coronate papillae do not seem to give way (by transition) to any 

 other type at the limit of the area on which they occur ; they 

 simply become less distinct, their rings of papillae becoming isolated 

 as a few scattered points. There are about 31 coronate papillae to the 

 square millimetre just in front of the anterior circumvallate papillae. 

 There are 8-15 papillae in the rings. The coronate papillae are 

 circular. Occasionally a secondary papilla is placed within the nng, 

 but such irregularity is not common. Tlie shape of these papillae is 

 exactly like those described as the anterior type oi Perameles, the 

 succession of cells being very similar (see paper referred to, p. .599). 

 Just above the tip, and on the tip itself, there appear to be 

 11-12 papillae in the rings, and here there are only 20 main papillae 

 to the square millimetre. They are oval in shape, and •2/5 nnn. in 

 length and -175 mm. in breadth. The posterior secondary- papillae 

 are much developed (fig. xxx. Plate LV.). The upward succession 

 of cells is very complicated in these papillae, even more so than that 

 of Perameles. The succession is shown in fig. xxx. (Plate LV.^. 



B. The Filiform Papillce. — These are probably tactile, as nerve- 

 fibres are very abundant close to and in them (with many nerve- 

 cells in the nerves about their bases). The epithelium is not 

 cornified, and (in common with the papillae in this position in all 

 Marsujiials) their function cannot be mechanical. It is probable 

 that the nerve-endings are of the most delicate intraepithelial kind, 

 and therefore invisible except by special treatment of the fresh 

 specimen. Mucous glands are very abundant near these papillae, 

 the ducts often opening beneath them. 



Thus this tongue commences a new type, chiefly characterized by 



