TONGUE OP OENITHORHYNCHUS PARADOXUS. 4G5 



of the tongue with the oral floor, while the latter is covered 



with a thick simple layer with long papillary processes, exactly 



like that of the fold {f, fig. 10). All over the tongue of this 



animal there is a great tendency for the subepithelial elements 



to penetrate between the cells of the epithelium. This is 



especially true of the interpapillary processes of the shallow 



groove, between the left gustatory area and the fold. Here in 



many cases great masses of connective-tissue corpuscles make 



up a considerable bulk of the interpapillary process, as is seen 



in fig. 9. Outlying corpuscles have processes which extend 



toward the mucosa, indicating the direction from which the 



intrusion took place. These have been often described before, 



but I believe never to such an extent as is here figured. The 



corpuscles never ascend above the lowest layer of the complex 



epithelium, corresponding to the rete Malpighii. The fine 



pointed papillie are always much bent as they pass through the 



complex layer, while they are quite straight in the simple 



epithelium (compare fig. 8, /^j and fig. 10,/' jw'). The complex 



epithelium ascends along the groove in front of the fold, and is 



continued into the pit (fig. 1). Here it is extremely thin 



('08 mm.), while the simple epithelium in front of the pit is 



many times as thick (over '5 mm,). So also behind the pit the 



epithelium becomes simple and comparatively thick. Thus the 



convex upper surface and sides of the posterior region, covered 



with simple epithelium, are completely surrounded by the 



dense complex epithelium prolonged backwards from the lower 



part of the overhanging surface, skirting the sides of this 



region and rising along the groove until it meets in the pit. 



Glands are only found in association with the gustatory areas 



and beneath the epithelium of the pit; the former are serous, 



while the latter appear to be mucous, and are very numerous, 



with few openings into the pit. It is probable that there are 



m ore numerous openings posteriorly, beyond the limits of the 



tongue in my possession, as I inferred from other specimens 



that a groove is continued backward from the pit, ending in a 



depression in front of the epiglottis. 



The whole of the sides and convex upper surface of this 



