1889.] MICROSCOPICAL JOURNAL. 181 



On the Gustatory Organs of Erethizow Dorsatus. 



By FREDERICK TUCKERMAN, 



AMHERST, MASS. 



Quite recently I received a fresh tongue of this species. I placed the 

 organ for a few days in a mixture of Mullet's fluid and alcohol, and 

 afterwatds transferred it to ordinary spirit, where the hardening was 

 completed. 



General Description of the Tongue. — The tongue is 76 mm. long, 

 19 mm. wide, and 16 mm. in thickness. It is free from the fraenum for 

 32 mm. The fore part of the organ is compressed laterally, and ter- 

 minates in a more or less pointed apex. The posterior dorsal region 

 is somewhat roughened by verrucose elevations, and is impressed ante- 

 riorly by a slight mesial groove from the gustatory area backwards. Near 

 the base is a median ridge with a shallow groove on either side. The 

 fungiform papillae are normal in structure, but few in number. There 

 are a few large ones, disposed in lineal series, above the line of junc- 

 tion of the upper surface and sides. At the posterior part of the papil- 

 late surface are two circumvallate papilla? situated one on either side of 

 the median line. The two papillae are 16 mm. from the base of the 

 tongue, and equi-distant from its lateral margins and from each other. 

 Placed between them are two small slit-like apertures, which may have 

 at some period contained bulb-bearing ridges. The papillae foliatae lie 

 well down on the sides of the tongue, their posterior limits being some 

 4 mm. anterior to the circumvollate gustatory area. 



The Circutnvollata Papillce. — These papillae are about 1.45 mm. in 

 breadth, and 0.60 in height. They bear on their upper part a great 

 number of secondary papillae overlaying, which is a thin stratum of 

 stratified pavement epithelium. Serous glands are plentiful both within 

 the bodies of the papillae and around their base. Their .ducts open into 

 the trench, especially at its deeper part. The taste-bulbs, which are 

 far from numerous, are disposed in a somewhat irregular belt around 

 the base of the papilla. They average about 0.054 mm - i n length, and 

 0.024 mm. in breadth. 



The Papillce Foliatcc. — The foliate papillae are about 7 mm. in 

 length. Each papilla consists of fifteen or sixteen fairly symmetrical 

 folds, and each fold bears at its upper part two or more secondary 

 papillae, the spaces between which are filled to a common level with 

 epithelium. The furrows separating the folds or ridges are narrow, 

 and 0.45 mm. in depth. Serous glands are abundant about the base 

 of the folds, and their ducts usually open at the bottom of the furrows. 

 The taste-bulbs are not numerous, and are very irregular in their dispo- 

 sition. They average 0.048 mm. in length, and 0.027 mm. in breadth. 

 - In the fungi form papillae the taste-bulbs seem to be relatively more 

 numerous than in the gustatory areas proper of the tongue. They are 

 situated at the upper part of the papilla, and are usually placed ob- 

 liquely to its long axis, with their apices directed upwards and out- 

 wards. The basal end of the bulbs generally touches the mucosa. In 

 transverse sections of these papillae the component cells of the bulbs 

 could frequently be distinguished without difficult}', and in one bulb I 

 counted twenty distinct cells. More than half of the cells were grouped 

 about the axis of the bulb, and were doubtless sensory in function. 



