302 



MAMMALIAN ANATOMY 



Dhmoidal cleft 

 -Cleft plate of M. 



attachments are not in contact with one another, but leave slits, which 

 are also seen on the external surface. There are no openings, how- 

 ever, between the second and third (ni', m") nor between the fourth 

 and fifth scrolls (4', 4"). 



The relation between the outer and inner scrolls is as follows (Figs. 

 220, 221). The first inner scroll (!') is distinct from the first outer 

 scroll (1"). The first, second, third, fourth, and fifth outer scrolls (1", 



2', 2", 3', 3") are hidden 



FIG. 221. completely on the inner 



surface by the second, 

 third, and fourth inner 

 scrolls (m', m", 4') and 

 the sixth and seventh 

 outer scrolls (4', 4") . The 

 sixth and seventh outer 

 scrolls (4', 4") appear on 

 the inner surface as the 

 fourth and fifth inner 

 scrolls (4', 4"). They 

 form also on the outer 

 surface the mass of small 

 anterior scrolls (Fig. 222, 

 4"'). The sixth inner 

 scroll (Fig. 219, 5) com- 

 prises the eighth and 

 ninth outer scrolls (5', 

 5"). The seventh inner 

 scroll (Fig. 219, 6) com- 

 prises the tenth and eleventh outer scrolls (6', 6"). The eighth inner 

 scroll (Fig. 219, 7) comprises the twelfth and thirteenth outer scrolls 

 (7', 7"). 



Each lateral ethmoid may be divided into eight pieces by cutting 

 the attachments of the scrolls to the cribriform behind and to the plate 

 which forms the posterior wall of the ethmoidal cleft in front. 



The first and superior piece of the lateral ethmoid is a rela- 

 tively large mass, oblong in shape, gently bowed upward, and slightly 

 larger at the anterior end. Its outer side (Fig. 223) exhibits the 

 median longitudinal partition (1), with a scroll above (!') and a scroll 



Vomer- 



Lachrymal canal 



TRANSVERSE VERTICAL SECTION THROUGH HALF OF FACE. 



Just anterior to second premolar. Cut surfaces black (somewhat 



diagrammatic). 



