DEVELOPMENT OF THE SKULL OF THE COMMON FOWL. 
805 
Figs. 9 & 10. Anterior and lateral views of stapes. X 24 diameters. 
Fig. 11. Part of palatal rod, from fig. 6. X 160 diameters. 
Fig. 11a. Peripheral cells of the same. X 820 diameters. 
Fig. 11b. Central cells of the same. X 320 diameters. 
Fig. 12. Mandibles and tongue from the above. X 12 diameters. 
Fig. 13. Proximal part of mandible of an embryo somewhat older. X 24 diameters. 
Third Stage. — Head of Embryo 8 or 9 lines long : middle of 2nd Week . 
Fig. 14. Transversely vertical section of auditory sacs. X 10 diameters. 
Fig. 15. Os hyoides. X 4 diameters. 
Fig. 16. Part of cartilaginous “ lingula sphenoidalis.” X 250 diameters. 
PLATE LXXXII. 
Third Stage (continued). 
Fisr. 1. Basal view of skull, with outer bones removed. X 10 diameters. 
O 7 
Fig. 2. Ditto, with splints and palatal bones. X 10 diameters. 
Fig. 2a. Part of the same, from above. X 10 diameters. 
Fig. 2b. Section of pterygoid. X 250 diameters. 
Fig. 3. Part of fig. 1, from above. X 13^ diameters. 
Fig. 4. Transverse section of “ sella turcica.” x 20 diameters. 
Fig. 5. Anterior part of notochord. X 250 diameters. 
Fig. 6. Posterior part of ditto. X 250 diameters. 
Fig. 7. Section of orbital septum and palatines. X 20 diameters. 
Fourth Stage. — Head of Embryo 10 to 12 lines long : end of 2nd and beginning 
of Zrd Week. 
Fig. 8. End of skull ; outer view. X 5 diameters. 
Fig. 9. End of skull ; inner view. X 5 diameters. 
Fig. 10. Half of the same, from within. X 5 diameters. 
Fig. 11. Alate portion of septum nasi. X 20 diameters. 
Fig. 12. Transverse section through occipital region. X 20 diameters. 
PLATE LXXXIII. 
Fourth Stage (continued). 
Fig. 1. Basal view of skull. X 4 diameters. 
Fig. 2. Upper ditto, with splints removed. X 4 diameters. 
Fig. 3. Front ditto, with orbital septum removed. X 4 diameters. 
Fig. 4. Section of skull with lateral parts removed. X 4 diameters. 
Fig. 5. Side view of orbital and nasal regions. X 4 diameters. 
