858 DE, C. F. SONNTAG ON THE VISCERAL ANATOMY 



and pass inwards to cover the posterior fourth of the ventral 

 surface of the neck. The glands are composed of numerous small 

 portions surrounded by connective tissue, but it is not always 

 possible to discern the ductules. They were prevented froni 

 reaching the mid line of the neck by the cervical thymic lobes in 

 my specimen of Trichosurus vulpecida, but Symington (17) saw 

 them cover the thymus in his. Although their extent is great 

 they are thin. 



Text-fiffure 71 



The neck of Macropus giganteiis. a. onio-hyoid; 6. thyroid gland; e. pretracheal 

 muscles ; d. fascia ; e. submaxillary gland ; f. mandible ; g. small gland ; 

 A. digastric; -i. mylo-hyoid ; y. larynx ; A. cervical thymus ; ?. sterno-mastoid; 

 in. parotid gland in outline. 



The Submaxillary Glands (e) are, generally speaking, large in 

 Polyprotodonts and small in Diprotodonts, but there are excep- 

 tions in the latter. They are large, single, and oval in the Didel- 

 phyidse and Dasyuridae, and in some of the former they reach from 

 the angles of the mandible to the clavicles. They are immense and 

 lobulated in Perameles ohesida (text-fig. 72), in which a copious 



