THE SALIVARY GLANDS 495 
crown of the first lower molar (Dens sectorius) is compressed laterally and has two 
pointed, sharp-edged lobes, behind which are one or two tubercles; it has two roots. 
The average periods of eruption are given below. 
ToorH ERUPTION CHANGE 
er ...4 to 5 weeks 
I, .4 to 5 weeks 1 to 5 months 
I3.. 4 weeks 
(ORE 3 to 4 weeks 4 to 5 months 
| een 4 to 5 months 
P; .4 to 5 weeks 5 to 6 months 
Pes = 3 to 4 weeks : f 
P, 3 to 4 weeks ) 
M, 4 months 
M upper 5 to 6 months 
=e * \ lower 44% to 5 months 
M .....6 to 7 months 
Fie. 436.—Base oF SKULL oF CocKER SPANIEL. 
Ii-3, Incisors; C, canine; Pi—4, premolars; Mi—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. 
