4 .F. Tuckeraian, 



plexus, in order doubtless to supply the bulbs lower down, but in 

 tracing these I was not very successful. 



Many of the papillae bear sensory terminal organs. Some of 

 these terminal organs are, I believe, unquestionably taste-bulbs; whilst 

 others (though structurally related), from their exposed positioii and 

 general appearance, I think function as tactile organs. The taste- 

 bulbs [see fig. 3] are far from numerous, but on account of their large 

 size can readily be seen with a low power. They measure 0.1 14 mm. 

 in length and 0.0.57 mm. in breadth. No separation of the bulbs into 

 sensory and protecting elements was attempted, but judging from a 

 superficial examination the number of their component cells appeared 

 to be very great. The bulbs are restricted to the lower portion of 

 the lateral area, and are wholly epithelial in position. They pass 

 through the epithelium somewhat obliquely, their bases being in con- 

 tact with the mucosa, while their pores open into shallow depressions 

 on the free surface of the epithelium. They are very irregular in 

 their distribution, and are isolated as regards position, it being but 

 seldom that two are found occurring together. 



The structiu'es which I am inclined to look upon as tactile rather 

 than gustatory organs, occur for the most part in the papillae near 

 the lateral margins of the tongue. They are not numerous, and are 

 disposed at the upper part of the papillae with their apices perforating 

 the superficial layers of the epithelium. They are fusiform bodies, and 

 are intra-epithelial in position. One of these tactile organs is shown 

 (together with its nerve) in fig. 4. As will be seen by reference to 

 the figure, only a portion of the terminal branches coming off enter 

 the terminal organ, the greater number being distributed to the ad- 

 jacent epithelium. 



I anticipated finding sensory terminal organs in the lingual papillae 

 of the vegetai-ian chelonians, and it is quite probable that fui-tlier 

 search may also reveal tlieii' presence in some of the carnivorous foiins 

 of this group. 



Amherst, Mass., Ü. S. A., 1.5 June 1891. 



