306 DEVELOPMENT OF SALIVARY GLANDS IN THE DOMESTIC CAT 



interval. They may arise from the parotid flange in the angle between 

 the duct and the oral epithelium, or from either the oral epithelium 

 or the duct itself. Their bodies, usually of small size, are coniined 

 to the triangle between the mouth, the parotid duct, and the masseter 

 muscle. In this confined space they may be parallel to the parotid, 

 or to the oral epithelium, or have an intermediate direction. Very 

 rarely larger sprouts tend to escape either towards the orbit or along 

 the inframasseteric path. In a few cases these elements were found 

 separated and forming inclusions. 



The parotid, orbitoparotid, and the sprouts referred to in the course 

 of the orbital inclusions, evidently constitute a series of buccal sulcus 



163. Schema of buccal sulcus and its derivatives, early stage. 



I. Buccal sulcus. 12. Parotid aulage. 



-'. .A.ngulus oris. 75. Orbitoparotid interval. 



6. Orbital inclusion. yj. Masseter muscle. 



derivatives modified in development by the presence of the masseter 

 (Fig. 165). 



4. The vestibule is formed by a remodeling of the maxillomandib- 

 ular plane. In this process the buccal sulcus is largely effaced, and 

 dorsal and ventral limits (alveobuccal sulci) are formed for the new 

 cavity by a simple process of folding in the roof and floor of the mouth. 

 With the appearance of the alveobuccal sulci, two sagittal strips of 

 epithehum are defined, intervening between them and the buccal 

 sulcus (Wangenstreifen, Chievitz), which are destined to form the 

 lining of the cheek. Of these the ventral is much the wider, corre- 

 sponding to the greater expansion of the floor of the maxillomandib- 



