182 



Charles Searing Mead. 



Lacerta, which has no floccuhis. In man its depth varies with 

 age — in the embryonic stages (Hertwig's model) it is only a shallow 

 pit; in children from two to ten years of age, it is a deep pit, com- 



l. par 



sul.fac. 

 cr.par. 



J ch.tu. 



Fig. 3. Section showing tlie broad basal plate h.p. and the hyoid arch hyo. 

 approaching the vestibular portion of the ear capsule, x 10- 



sin. tr., sinus transversalis ; VIII, nergus aeusticus ; sul.fac, sulcus facilis ; 

 cr.par., crista parotica ; ch.ty. chorda tympaui ; VII, nervus facialis ; X r.aur., 

 ramus auricularis of the vagus nerve ; X, main portion of the vagus ; XII, 

 nervus hypoglossus; n.c, notochord; i.j.v., internal jugular vein; tn.st., mus- 

 culus stapedialis; sac, sacculus; J.s.c, lateral semicircular canal; utr., utricu- 

 lus ; a.s.c, anterior semicircular canal ; l.par., lamina parietalis ; pa., anlagen 

 of parietal bone. 



parable to that in the adult dog, while in adults it becomes again 

 only a shallow depression. Skulls of adult Lepus show a deep pit, 

 as do also the embryos, and the same is true of Macacus and Semno- 

 pithecus. In the adults of Sus the pit is shallow. From the con- 



