38 THE DEVELOPMENT OF THE SALIVARY GLANDS IN MAN 



general analog^' of development here with that in the cat seems to 

 confer a high degree of probability upon the assumption of its tem- 

 porary' existence. 



The sections through the posterior portion of the pedicle of the 

 parotid throw some light on the method of its separation. Here the 

 horizontal portion of the pedicle appears destined to reduction. In 

 Fig. 14, jS, it presents two incisures ventrally. In the next section 

 (Fig. 15, jS) a very small mass of cells is interposed between the 

 parotid and the buccal sulcus. This occupies the position not infre- 

 quently assumed by the orbitoparotid in the cat, which, in some cases, 

 springs from the angle between the parotid duct and the oral epithe- 

 lium. On the left side there is no trace of this element. 



The orbital inclusion (Figs. 4, 5, 17-19, j) is separated from the 

 oral epithelium by a small amount of mesenchyme. It corresponds to 

 almost the whole postparotid segment of the buccal sulcus, the course 

 of which it follows on a slightly ventral plane. Its two extremities are 

 slightly enlarged, the intervening portion being extremely tenuous. 

 The center in section is pale at the enlargements, but a lumen cannot 

 definitely be made out. though some sections suggest it strongly. No 

 notable difference obtains between the two sides. The buccal nerve, 

 which is lateral to the inclusion posteriorly, crosses it ventrally near 

 the orbital angle and continues forward mesad of the cranial portion of 

 the inclusion and of the parotid. At the point of crossing the inclu- 

 sion is closely applied to the nerve. 



The following measurements obtained by section counts may serve 

 for comparison with other embryos. 



Right Left 



Angulus oris to parotid 4256 f- 425-6 /* 



Sagittal length of parotid 159-6 /i 186.2/1 



Attachment of parotid 53.2 fi 66.5 /i 



Orbitoparotid interval 53.2 /x 66.5 fx 



Average length of orbital inclusions 432.2 /i 



8. Chievitz. Embryo of 8 weeks. The attachment of the parotid 

 is fundal, practically in the same plane as that of the submaxillary. 

 Thence the duct extends caudad 0.26 millimeter. The fundus lies 

 on the lateral surface of the masseter. In the seventh figure of his 

 paper an interesting outline is given of this parotid at its attachment. 



