132 



PHYSIOLOGY 



CHAP. 



Finally, it is worth noting that during development the 

 number of taste-buds continually decreases. In fact it has been 

 demonstrated that in children the median portion of the dorsum 

 of the tongue, as well as other regions of the oral cavity, are 

 provided with taste -buds, and therefore with gustatory sensi- 

 bility. This was first discovered by Urbantschitsch and sub- 

 sequently confirmed by Kiesow, Stahr, and others. Stahr found 

 forms of gustatory papillae in the centre of the infant's tongue 

 that entirely disappear later on. Ponzo made further histological 

 researches under Kiesow, and found taste-buds in the human 

 foetus on the anterior and 

 posterior pillars, as well as 

 in the epithelium that 

 covers the palatine tonsil 

 and the mucous membrane 

 that covers the nasal surface 

 of the lateral parts <f the 

 soft palate. The taste-buds 

 there are borne on high com- 

 pound papillae, character- 



FIG. 58. Compound papilla from dorsal 

 part of soft palate of a human foetus 

 (female) at term, with a taste-bud 

 on the left side. (Ponzo.) 



Fio. 59. Nodule of adenoid t issue from the lateral 

 wall of the nasal pharynx, near month of 

 Eustachian tube, in human foetus (female) at 

 term, with taste-bud. (Ponzo.) 



istic of this kind of mucous membrane, which has a stratified, 

 ciliated cylindrical epithelium (Figs. 58, 59). 



Ponzo has also demonstrated the existence in the new-born of 

 taste-buds in the pharyngeal part of the larynx, cervical part of 

 the oesophagus, and the hard palate. His discovery in the new- 

 born infant of taste organs upon the plicae fmibriatae of the tongue 

 is important in phylogenesis, as they are more developed than in 

 the adult, and must be considered as a vestige of the inferior 

 accessory tongue of the pro-simians and of certain apes, in its 

 turn a rudiment of an earlier form of non- muscular tongue 

 (Gegenbaur). According to Giacomini this is more constantly 

 present and even better developed in the negro race than in our 



