484 



Mr. H. T. Butlin. 



[Apr. 24, 



I. " On the Nature of the Fur on the Tongue." By Henry 

 Trentham Butlin, F.R.C.S. Communicated by J. BiTRDON 

 Sanderson, F.R.S., Professor of Physiology in University 

 College, London. Received March 26, 1879. 



[Plates 10—13.] 



The fur on the tongue is generally stated to consist chiefly of 

 epithelial cells, usually sodden and granular. But several observers 

 have described fungi as existing in it, or in the buccal mucus. Robin, 

 for instance, describes a form of L&ptothriw (L. Buccalis) in the 

 mouth, and particularly in and between the teeth. Kolliker mentions, 

 as of constant occurrence, masses or dark-brown bodies (which had 

 previously been described by Miquel and Neidkardt, as occasionally 

 present) having a granular aspect, which he believed to be of the 

 nature of a fungus, similar if not identical with the fungus affecting 

 the teeth. Billroth speaks of finding in the white fur of himself and 

 of several patients, exquisite palmelloidal forms of Ascococcus and 

 Glcecocctis colonies. 



The object of this paper is to show that schizomycetes form the 

 essential constituent of the fur, and to explain, as far as possible, some 

 of the laws which govern the formation of far. 



The tongue is kept clean by free movement and by being rubbed 

 against the interior of the mouth, the gums, and the teeth ; but fur 

 almost always exists upon its surface, both in health and in disease. 

 The fur is generally thickest in the morning before food is taken, and 

 during illness, when the necessary cleansing is not properly performed. 

 It occurs, too, most abundantly in the centre and back part of the 

 tongue, covering a triangular area immediately in front of the circum- 

 vallate papillae, for this part of the tongue is most difficult to keep 

 clean. It occupies the papillary surface of the tongue, scarcely ever 

 extending beyond it, and is, therefore, not found posterior to the 

 circumvallate papillae. It does not form a continuous layer unless it 

 is exceedingly thick, but lies upon the tops of the filiform and some 

 of the fungiform papillae. In children the fungiform papillae are 

 usually quite free from fur, but in adults the difference between the 

 fungiform and filiform papillae is not nearly so well marked, and, with 

 the exception of those situated near the apex of the tongue, the 

 fungiform papillae are frequently coated. Fur forms upon the filiform 

 papillae, because these papillae are rough and possessed of longer or 

 shorter epithelial processes, to which foreign matters cling readily, 

 and from which it is very difficult to dislodge them. The fungiform 

 papillae, on the contrary, are usually smooth and rounded on the 

 summit, and even when large are easily kept clean. 



