THE SALIVARY GLANDS 



495 



crown of the first lower molar (Dens sectorius) is compressed laterally and has two 

 pomted, sharp-edged lobes, behind which are one or two tul)ercles; it has two roots. 

 The average periods of eruption are given below. 



Tooth Eruption 



Ii 4 to 5 weeks 1 



}' f t° 5 weeks '.'.'.'.'.'.'.'.'.'.'.'.'..'. 4 to .5 months 



la 4 weeks 



g 3 to 4 weeks .■.■■.■.■.■.'.■.■.■.■.■.■.■.' .' .' 4 to 5 months 



■r 1 4 to 5 months 



Pa 4 to 5 weeks 



Ps 3 to 4 weeks 



P4 3 to 4 weeks 



Ml 4 months 



lyj f upper 5 to 6 months 



* 1 lower 4}^ to 5 months 



M3 6 to 7 months 



Change 



5 to 6 months 



Fig. 436. — Base of Skull op Cocker Spaniel. 

 Jl-S, Incisors; C, canine; Pi-4-t premolars; Ml-2, molars. Note the crowding of the canines and premolars on 



account of the shortness of the jaw. 



THE SALIVARY GLANDS 



The parotid gland is small and is irregularly triangular. Its dorsal end is wide 

 and is divided into two parts by a deep notch into which the base of the ear is 

 received. The ventral end is small and overlaps the mandibular gland. The 

 parotid duct leaves the gland at the lower part of the anterior border, crosses the 

 masseter muscle, and opens into the mouth opposite the third upper cheek tooth. 



