TONGUE AND GUSTATORY ORGANS OP MEPHITIS MEPHITIOA. 159 



(though this is not constant) and more shallow. This pedun- 

 culated arrangement of the base of the papilla accounts for its 

 free mobility, first noticed iu the superficial examination. In 

 some sections the trench is so extremely narrow that the 

 surfaces of the opposing walls are almost contiguous. The 

 width of the trench is usually greater in its upper portion, 

 becoming, in most cases, gradually narrower as it curves down- 

 wards and inwards. The outer wall reaches nearly to the level 

 of the upper surface of the papilla. Serous glands are present 

 in the body of the papilla, but both mucous and serous glands 

 (the latter being the more numerous) are very abundant in this 

 region of the tongue. The ducts of the serous glands open 

 into the trench, either at its sides or where it passes beneath 

 the papilla. They are very plentiful. In one small horizontal 

 section I counted twelve separate (?) ducts. Towards its 

 upper part the papilla carries many secondary papilla?, the 

 depressions between them being filled by epithelium. The 

 nerves are mainly non-medullated. They form a network in 

 the upper part of the papillary axis, from which branches 

 radiate outward towards the lateral margins, terminating, appa- 

 rently, at or near the bases of the taste-bulbs. 



The taste-bulbs are very numerous in the circumvallate 

 papillae. They are distributed along the sides in a zone of ten 

 or twelve tiers or rows, but are most thickly placed at the 

 under surface of the papilla facing the bottom of the trench. 

 The bulbs in this situation, although protected to a remarkable 

 degree, are often smaller and less fully developed than else- 

 where. I counted here, in one horizontal section, a group of 

 forty-five on a surface 0*3 mm. square. The estimate of the 

 number of these structures cannot be very exact. In one 

 quarter of a horizontal section, made at the lower third of the 

 papilla, I counted fifty-five bulbs. If we allow 200 in each 

 tier, and allow ten tiers, we shall have 2000 bulbs for each 

 papilla, or 4000 for the two. Bulbs are also present in the 

 epithelium bordering the mid-trench (fig. 3) between the two 

 large divisions of the papilla. Iu one section I met with them 

 (fig. 3) on the free upper surface. I likewise found them in 



