SEROUS GLANDS OF THE VALLATE PAPILLAE 375 



at birth nor even at five years. At twenty-two years simple 

 outgrowths and anastomoses are still present (fig. 9). 



Schmidt ('96) and Erdheim ('04) have described several 

 cases in which cystic glands are found associated with the thy- 

 reoglossal duct, or, as isolated structures containing no ducts. 

 In the present study, the occurrence has been noted of a spheri- 

 cal, thyroid-like mass, made up of follicles and containing a 

 colloid-Hke substance, situated in the base of the tongue of a 

 19 cm. specimen. In another specimen dilatations of the ducts 

 of some of the serous glands of the anterior papillae have been 

 observed. A homogenous mass filled the cystic parts, and a 

 duct connected the largest cyst to the groove surrounding the 

 papilla. It appears, therefore, that besides the cystic glands 

 associated with the thyreoglossal duct, cystic enlargements of 

 serous glands of the tongue might also occur. 



Frequently taste buds are found on the dorsal surfaces of the 

 vallate papillae in the newborn. In other specimens they are 

 noted only incidentally and occasionally are reconstructed mth 

 the papillae. It has been stated above that in some of the 

 newborn and older specimens, mucous glands intermingle with 

 serous glands and join with the ducts of the latter. This condi- 

 tion has also been observed by Maziarski and others. It is 

 possible therefore that the ducts and glands of the vallate pa- 

 pillae although usually serous in type are capable of developing 

 mucous cells or alveoli or of being transformed into mucous 

 alveoli, or that secondary connections are established between 

 mucous end-pieces and the ducts of serous glands. It is note- 

 worthy that mucous alveoli joined to ducts of the serous glands 

 are observed only in adult material. 



From the distribution of the blood vessels in the gland groups, 

 it does not appear that the latter conform to our usual concep- 

 tion of lobules or histological units of organs. 



CONCLUSIONS 



Serous glands first appear in 8.5 cm. fetuses as outgrowths, 

 originating usually from the lower border, but sometimes from 

 the outer wall of the vallate papilla. 



