642 



DR. C. F. SONNTTAG ON THE COMPARATIVE ANATOMY 



Owen (27) stated that they are plain in the Mystacoceti, but 

 Wyman (35) described lobules in B. borealis. Schulte (29), how- 

 ever, did not figure them in the foetus of that species. 



It is difficult to decide where the oi-al and pharyngeal parts of 

 the tongue meet in many species, for vallate papillae are frequently 

 absent. In Orcella fulminalis the base is delimited by a sulcus, 

 whose ends correspond to the angles of the mouth. And many 

 glands open into the sulcus (1). 



Sidci : — Median dorsal a,nd median ventral sulci are absent in 

 most cases. But many fine longitudinal and transverse sulci 

 may be present. In Orcella they feel gritty to the touch. 



The tongue may be smooth and plain all over, as in the foetal 

 Balcenoptera borealis. It is wrinkled all over in Orcella hrevi- 

 rostris. In many species the posterior part of the dorsum is 



Text -figure 26. 



Tongues of the Cetacea. A: Grampus griseus ; B: Lagenorh^/nchus albirostris ; 

 C: iJelphinus delphis; s : glandular sac. 



divided into areas by sulci. The inferior surface is more or less 

 corrugated, and may rest on a cushion formed by folds of the 

 mucosa of the floor of the mouth. The degree of corrugation 

 varies at different ages, for Anderson (1) showed that the tongue 

 in the young Platanista gangetica is smooth, but its i-oot is 

 corrugated in the adult. In Cephalorhynchus eutropia a thick 

 fold surrounds the tongue below the apex. 



Glands: — The most marked features on the tongues of the 

 Cetacea are the orifices of innumerable glands, and nearly every 

 account records their presence. They vary greatly in extent and 

 prominence, and they are more numerous than in all other 

 Mammalia, 

 " Genus Orcella : — In 0. fulminalis many racemose glands open 



