OF THE TONGUES OF THE MAMMALIA. 645 



Grampus griseus (text-fig. 26 A) has neither filiform nor fungi- 

 form papilliB. At the junction of the oral and pharyngeal parts 

 of the tongue there are two i-ows of deep narrow slits in V-for- 

 mation, but there is no mesial sulcus. Each row has six fissures. 

 In the specimen in the Museum of the Royal College of Surgeons 

 they are absent. 



Owen (37) described four lai"ge fossulate papillte in Hyperoodon. 

 But Turner (34) recorded many crypt-like depressions and 

 papillae, and a vallate V in Mesoplodon bidens. In my specimen 

 of M. hidens there are five large sacs, probably glandular in 

 ■character. 



In Cephalorhynchus eutropia (text -fig. 25 B) there are no 

 filiform or fungiform papillae. Between the oral and pharyngeal 

 parts of the tongue are five fissures in V-formation. 



In Delphinus delphis (text-fig. 26 0) the slits have closed lips. 

 In Deljjhinapterus leucas (text-fig. 27 B) they are longer, and 

 the lips of one are opened to disclose a row of globular bodies. 

 Phoccena communis (text-fig. 27 A) has eight small fissures placed 

 end to end in V-formation. 



Neither papillae nor fissures are present in Monodon monoceros, 

 Lagenorhynchus alhirostris (text-fig. 26 B), Delphinus phoccena, 

 ^nd Balcenoptera horealis. 



In no Cetacean is there any trace of lateral organs. It appears, 

 therefore, that the gustatory function is practically absent. 



The Inferior Surface of the Tongue is usually folded, both 

 longitudinally and transversely, and its mucosa is usually soft 

 all over. But there is a firm bounding zone in Grampus griseus, 

 Lagenorhynchus alhirostris, and Physeter macrocephalus. Some 

 forms have glandular pits beneath the apex. In no case did I 

 see any trace of a sublingua or plicae fimbriatae, but Schulte (29) 

 described a small tr-iangular sublingua in the foetal Balcenoptera 

 horealis. 



The fremcm is absent in DeljjMnapierus leucas and Mesoplodon 

 'bidens. It is slight in Grampus gi-iseus, Lagenorhynchus alhi- 

 rostris, Cephalorhynchus eutropia, and Phoccena comimmis. 

 Schulte (29) said it is absent in the foetal Balcenoptera horealis. 

 Anderson (1) described it in the foetal Orcella hrevirostris, but 

 said it is absent in the adult. I observed a very marked frenum 

 in the new-born Physeter macrocephalus (text-fig. 25 A). These 

 observations would show that the Cetacea require a frenum 

 -while suckling, but not when they lead an independent existence. 



No Cetacean has salivary papillae or plicae fimbriatae. 



Summary. 



1. The tongues of the Cetacea have their glandular organs 

 iDetter developed, but their gustatory and mobile functions are 

 less, than in other Mammalia. 



44* 



