1894.] 



MICROSCOPICAL JOURNAL. 



139 



such papillfB are formed of epidermal cells flattened down 

 and pressed together the shape of the mass being im- 

 parted by their formation on the surface of dermal pap- 

 illa of different kinds. In order to demonstrate the sen- 

 sory function of the tongue other sections in special parts 

 of the organ are necessary. 



The salivary glands are also a part of the mouth 

 though not located in it. There are several different 

 ones, the most convenient one to study is the " parotid " 

 which as its name implies lies beside the ear. It lies a 

 little below that organ. Sections properly hardened and 

 sliced will show the parts displayed in the adjoining fig- 

 ure, the organ in the main is a mass of rounded areas of 

 various shape, in places 

 elongate passages are visi- 

 ble, and perhaps a connec- 

 tion between the rounded 

 areas and these passages 

 will bediscernable. Besides 

 these two there will also be 

 seen in places, views of ar- 

 teries. Some veins will Parotid gland of cat. 

 perhaps also be discovered but unless the section is 

 injected the vascular structure will be only very inade- 

 quately shown. The nerves will be undistinguishable 

 from the areolar connective tissue, spread out everywhere 

 between the divisions of the gland. Since the glands are 

 of the racemose type, the terminations of the ductules 

 will appear as closed portions, with a cavity the " lumen " 

 in the centre. The section here represented is such a 

 slice as would be obtained by a cut through the organ in 

 any plane vertical to the surface. At first the section 

 will appear to the untrained eye as a confused mass of 

 faintly colored spots, but by degrees the eye will analy- 

 ize the confusion and the principal structural elements in 

 their relation will be discerned. The section here repro- 



Lunien 



/\lveoIus 



Demi -lune 



