PAPILLA FOLIATA. PALATK. 09 



Papilla foliata. T.S. of, in the root of the rabbit's tongue, 

 (p. 3, s. 22 & 24, c. P., m. B.) The papilla projects slightly 

 above the general level of surface of the tongue and consists 

 of a series of vertical clefts (sulci) which indent its surface, 

 and are lined by the superficial stratified epithelium. In 

 this epithelium, on each side of the sulcus, the taste buds 

 are placed. Find the secreting portions of the serous glands 

 situated at some depth in the muscular tissue of the tongue 

 and trace their ducts, which open into the sulci. Outside 

 the foliate area mucous glands similarly disposed will be 

 found, and are easily recognised by the transparent character 

 of their epithelium. (//) Examine the taste buds. They 

 are oval masses composed of fusiform cells arranged after the 

 fashion of the staves of a barrel, the axis of which is set 

 vertically to the sulcus. The pointed apex of the bud cor- 

 responds to an opening in the surface, the gustatory pore, 

 through which the inner set of cells of the bud project as a 

 cluster of minute short bristles. Outside the bases of the buds 

 modified fibrous papillae form an access for the nerves going 

 to the buds. Compare the cells in the serous glands with 

 those in the mucous glands and find large nerve bundles 

 which run towards the surface. 



Soft palate. V.S. Dog. (p. 3, s. 22 & 24, c. P., m. B.) (L) 

 and (ff) Recognise the mucosal surfaces covered on the 

 nasal side by stratified ciliated, and, on the oral aspect, by 

 stratified squamous epithelium. Between these there is striped 

 muscle loosely arranged (Azygos uvulse, etc.) and mucous 

 glands, the ducts of which open on both surfaces. 



The preparations of the remainder (tubular portion) of the ali- 

 mentary canal which follow this resemble each other in the general 

 plan of their construction. All of them have three concentric coats. 

 (1) Mucous, (2) Sub-mucoi#, (3) Muscular, to which externally a fourth 

 or Serous coat of varying extent is added in the peritoneal cavity. 



