336 



ON THE DEVELOPMEMT OF THE SKTJLL IN THE PIG. 



PLATE XXXIV. 

 Fourth Stage (continued). 



Fig. 1. Side view of skull. X 3^ diameters. 

 Fig. 2. Lower view of same. X ^\ diameters. 

 Fig. 3. End view of same. X 3^ diameters. 



Fig. 4. Upper occipital region of a somewhat younger embryo. X 3^ diameters. 



Fig. 5. Section of skull (vertical). X 3|- diameters. 



Fig. 6. Bird's-eye view of primordial skull. X 3^ diameters. 



Fig. 7. Inner view of compound mandible. X 3^ diameters. 



Fig. 8. 1st section through nasal region, X 7 diameters. 



Fig. 9. 2nd section of same part. X 7 diameters. 



Fig. 10. 3rd section through nose. X 7 diameters. 



Fig. 11. 4th section of same, x 7 diameters. 



Fig. 12. 5th section through inferior turbinal. X 7 diameters. 



PLATE XXXV. 



Sixth Stage. — Emhrijo Pig, 6 i7iches long. 



Fig. 1. Side view of skull, x 1-2 diameter. 



Fig. 2. Lower view of same, x li diameter. 



Fig. 3. Vertical section of same. X 1^^ diameter. 



Fig. 4. Bird's-eye view of primordial skull. X 1^ diameter. 



Fig. 5. Outer view of occipital and auditory regions. X 2 diameters. 



Fig. 6. Transversely vertical section through inferior turbinals. X 3 diameters. 



Fig. 7. Another through ethmoids. X 3 diameters. 



Fig. 8. Part of section through hinder part of nasal labyrinth, x 3 diameters. 



Fig. 9. Section through orbits. X 2 diameters. 



Fig. 10. Part of section through anterior sphenoid. X 3 diameters. 



Fig. 11. Section through hinge of lower jaw. X 2 diameters. 



Fig. 12. Section through pcriotic mass and basioccipital. x 3 diameters. 



PLATE XXXVI. 



Seventh Stage. — l*ig at hirth. 



Fig. 1. Under view of sncut-cartilagcs. X 5 diameters. 



Fig. 2. Auditory capsule, hyoid, and occiput. X o\ diameters. 



Fig. 3. Auditory chain of bones. X 5 diameters. 



Eighth Stage. — Pig, G months old. 

 Fig. 4. Lower view of skull. Natural size. 



PLATE XXXVII. 

 Fig. 1. Side view of same. Natural size. 

 Fig. 2. End view of same. Natural size. 

 Fig. 3. Side view of lower jaw. Natural size. 



