SCHULTE, SEI WHALK. 431 



described it as an independent muscle m. costalis, but Stannius concurs with Meckel in 

 assigning it to the system of the transversarius, which it continues forward upon the thorax. 

 The transversarius arises by a series of slips from the side of the last vertebra and from the 

 transverse processes of the caudal, lumbar and thoracic vertebrae. It is inserted similarly by 

 slips into the transverse processes of more rostral vertebrae and in the thoracic region into the 

 ribs. The inferior division in the pedicle has an analogous arrangement ventral to the trans- 

 verse processes, arising from the side of the last vertebras and from transverse processes, insert- 

 ing into more rostral transverse processes. It becomes much reduced near the level of the 

 vulva and its remnant there merges with the portion situated dorsal to the transverse processes. 



THE UPPER ALIMENTARY TRACT. 

 (Plate LXIX, Fig. 1.) 



Cavurn oris proprium. In the absence of prominent alveolar processes, though in the 

 case of the maxillae this requires some qualification, the dento-labial sulci may serve as the 

 boundary between the vestibule and the mouth cavity proper. The course of the sulci has 

 already been described. On dissection the inferior furrow was found to send ventrad into the 

 alveolar gutter of the mandible a low keel, to which the dental anlages were attached or at least 

 immediately adjacent. These were in general subhemispherical, about 1 mm. in diameter, 

 although a few were slightly elongate sagittally. In the midregion they were separated by 

 intervals about equal to the anlages in length, but towards the symphysis they were more closely 

 set. The caudal third of the series was damaged by a crushing of the brittle jaw which occurred 

 during dissection, so that their shape could not be satisfactorily determined. The total number 

 was about thirty. The superior dento-labial sulcus was deepened along the margin of the 

 maxilla, but had no dental anlages attached to it. These were contained in the cavity of the 

 maxilla, which in its caudal two thirds presented a corresponding convexity on its palatine 

 aspect, which would seem therefore equivalent to a alveolar process. 



The floor of the oral cavity comprises the alveolingual region and the tongue. The alveo- 

 lingual region is very extensive and is the expression of the disparity in size between the tongue 

 and the wide arch of the mandibles. Its floor is wrinkled and furrowed, but upon depressing 

 the tongue and so stretching the mandibular pouch, these surface markings are effaced and 

 appear therefore to be but the accompaniments of the distensibility of the region. 



The tongue is broad and squat, rising but moderately above the alveolingual region. It 

 has a length of 48 mm. and its greatest breadth is 24 mm. Its tip is free for a sagittal distance 

 of 11 mm. In spite of its great size the tongue comes far short of filling the enormous mouth, 

 and there is at its sides a space of 1 or 2 mm. between it and the mandibles, while its tip fails 

 of reaching the symphysis by 7 mm. Similarly between the base of the tongue and the faucial 

 orifice there is an interval of 6 mm. Here the floor of the mouth is depressed to a shallow fossa, 

 the mucosa of which is marked by fine grooves and ridges. This depression is situated entirely 

 rostrad of the hyoid. Its floor forms a prominence between the hyoglossi and is reinforced by 

 a local increase of the transverse lingualis. Its presence appears to be associated with the 

 feeble development of the radix linguae. These facts and especially its position seem to pre- 

 clude all attempt to bring it into any direct relation with the pharyngeal pouch of the elephant 



