DEVELOPMENT OF THE SKULL IN THE PIG. 



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pcj. pterygoid, 

 p.f/r. processus gracilis. 

 p.ii. prenasal cartilage. 

 'p.n.w. posterior nasal wall. 

 p.oc. paroccipital, 

 p-p-f. posterior palatine foramen. 

 P-pg. palato-pterygoid. 

 p.p. palatine floor of palatine. 

 p.px. palatal part of premaxiUary. 

 pr. promontory. 

 pro. prootic. 

 ps. presphenoid. 

 p.sc. posterior semicircular canal. 

 py. pituitary body. 

 rc.c. recurrent cartilages. 

 s.c.i. short crus of incus. 

 s.m.f. stylo-mastoid foramen. 

 s.n. septum nasi. 

 so. supero-occipital. 

 s.pa. soft palate. 

 sp.s. sphenoidal sinus, 

 sg*. squamosal. 

 s.t. sella turcica. 

 St. stapes. 

 st.h. stylohyal. 

 st.m. stapedius muscle. 



t.c. tympanic cavity, 

 t.cb. tentorium cercbelli. 

 t.f. temporal fossa. 

 tg. tongue. 

 th.Ji. thyrohyal. 

 t.p. tooth-pulp. 

 tr. trabecula. 

 tr.cm. trabecular commissure. 

 t.tij. tegmen tympani, 

 ty. tympanic. 

 u.l. upper lip. 

 u.tb. upper turbinal. 

 V. vomer. 

 vh. vestibule. 

 z.mx. zygomatic process of maxillary. 

 z.sq. zygomatic process of squamosal. 



1. olfactory nerve. 



2. optic nerve. 



5". ophthalmic nerve. 

 5*. main part of 5th nerve, 

 7". portio dura. 

 1"'. chorda tympani. 

 7'. portio mollis. 

 8". glossopharyngeal. 

 8'. vagus. 

 9. hypoglossal. 



Description of the Plates. 



PLATE XXVIII. 



First Stage. — Emhryo Pig., f inch in length. 



Fig. 1. Side view of upper part of embryo. X 7 diameters. 

 Fig. 2. A plan of the same, with facial arches. X 7 diameters. 

 Fig. 3. A front view of the same. X 7 diameters. 



Fig. 4. A palatal view of the same, with the mandible and lower face removed. X 15 

 diameters. 



Fig. 5. A plan of the skull and face, seen from below. X 10 diameters. 

 Fig. G. A vertical section of the head. X 10 diameters. 



Fig. 7. Part of the same, with median part of nasal region removed. X -0 diameters. 

 Fig. 8. Upper view of a horizontal section of the head, x 10 diameters. 



PLATE XXIX. 



Fig. 1. Transversely vertical section of the nose, in front, X 12 diameters. 



Fig. 2. A similar section through the middle of the nasal region. X 12 diameters. 



Fig. 3. Another section through the posterior nasal region. X 12 diameters. 



