MINOT ON THE TONGUE 



I. Anatomy of the Snake's Tongue. 



The mouth of snakes is a spacious cavity leading into the wide oesophagus. Upon its 

 lower floor, a short distance behind the anterior end of the mandibles, are two openings 

 in the median line ; one, the anterior, leads into the sheath of the tongue ; the other 

 immediately behind the first, is the rima glottidls. The surface of the floor has numex'ous 

 longitudinal folds, which partially disappear Avhen the mandibles are divaricated. Over 

 the trachea there is a ridge in the floor of the mouth, which is also flattened out when 

 the jaws are pulled apart laterally. By these means the extension of the inelastic epi- 

 thelium is provided for. " 



A vertical transverse section, cut 1, through the opening of the trachea, shows the 

 relative size and position of the parts. The folds of the buccal epithelium are each sup- 

 ported by an extension of the fibrous submucosa, the 

 epithelium itself consisting of beaker cells. The folds 

 cease abruptly at the entrance of the glottis, gl, and the 

 height of the epithelium rapidly diminishes. Two cartil- 

 ages, c, lie on either side of the rima, which is also sur- 

 rounded by longitudinal muscular fibres, arranged in 

 seven bundles, one underneath, and three on each side. I 

 could find no trace of circular fibres. The sheath, s, of the 

 tongue follows immediately underneath the muscle, but 

 in my sections has been pressed away in mounting. It is 

 more than twice the diameter of the rima glottidls, but 

 further back the trachea and the linQ;ual sheath are of 

 the same diameter. In the interior of the sheath lies the 

 tongue, at this point entirely free. Underneath the sheath 

 is a very large gland, g, which I have seen in Eutaenia only. I overlooked it at first, 

 and cannot therefore say, whether it occurs in Ancistrodon or Crotalus. As fiir as I am 

 aware, no similar glands have been previously noticed in the Ojihidia. It extends for a 

 considerable distance along the median line. Further observations are necessary to 

 determine whether it is homologous with the sublingual glands of other vertebrates. 

 On either side are the cut ends, m. g. v., of M. genio-vaginli, the fibres being united into 

 three bvmdles on either side. The 31. genio-tracheales and retractor tracheae do not 

 appear in this section, the former being too distant laterally, the latter not extending so 

 far forward. 



The tongue, as a whole, may be said to consist of three parts : — 1, the free 2'>art forked 

 in front ; 2, the hase, or attached portion, lying under the trachea, and connected with 

 the hyoid cornu ; 3, the sheath, into which the free ^jart can be withdrawn. The follow- 

 ing points must be mentioned, because they have hitherto been either overlooked, or 

 insufficiently described. If the tongue and sheath be cut out, they appear as in fig. 1, 

 which represents the tongue of the rattlesnake, Crotahts durissus. The same figure 

 shortened by about three-quarters of an inch, would correctly represent the tongue 

 of the moccasin. The distance to which the tongue is free, is shown by the pig- 

 ment on its dorsal surface ; the dark color shines through the sheath, but does not 



Cut 1. Frontal section through the Jiima 

 qlottidis and linorunl sheiith of EuUitnia serta- 

 lis. gl, rima glottidis; c, cartilages; m, epi- 

 tracheal muscle; s, sheath of the tongue; 

 m. I/, v., musculus geniovaginius; g, gland. 



