334 
ME. W. K. PAEKEE ON THE STEUCTUEE AND 
Fig. 4. Horizontal section below the cranial cavity, exposing first arch, notochord, and 
investing mass. X 10 diameters. 
Fig. 5. A subhorizontal section through the eyes and root of tongue. X 10 diameters. 
Fig. 6. Part of the head, with outer part of cheek pared away. X 12 diameters. 
Fig. 7. A section made through the plane of the hinder part of cranium. X 12 dia- 
meters. 
Fig. 8. Part of same section. X 20 diameters. 
Fig. 9. A similar section. X 26 diameters. 
Fig 10. Another subhorizontal section through the top of the first postoral cleft. X 20 
diameters. 
PLATE XXX. 
Second Stage. — Embryo Pig, 1 inch long. 
Fig. 1. Section across the end of the shout. X 10 diameters. 
Fig. 2. Section through ethmoid region, root of tongue, and larynx. X 12 diameters. 
Fig. 3. Section nearly in plane of the notochordal region, front view. X 10 diameters. 
Fig. 4. A similar section, lower down. X 10 diameters. 
Fig. 5. Part of a similar section through apex of mandibular arch, front view. X 15 
diameters. 
Fig. 6. A similar section through apex of next arch, front view. X 15 diameters. 
Fig. 7. Another similar section through periotic capsule in plane of horizontal canal. 
X 10 diameters. 
Third Stage. — Embryo Pig, 14 inch long. 
Fig. 8. Part of a section through top of second postoral arch, corresponding with fig. 6 
of second stage, front view. X 15 diameters. 
Fig. 9. Side view of the three postoral arches. X 15 diameters. 
PLATE XXXI. 
Third Stage (continued). 
Fig. 1. 1st section through nasal region, x 7 4 diameters. 
Fig. 2. 2nd section of same. X 7| diameters. 
Fig. 2 a . Part of fig. 2. X 22^ diameters. 
Fig. 3. 3rd section of same. X 7| diameters. 
Fig. 3“. Part of same section, x 22^ diameters. 
Fig. 4. 4th section of same, x 7| diameters: 
Fig. 5. 5th section of same. X 7| diameters. 
Fig. 6. 6th section of same. X 74 diameters. 
Fig. 6°. Part of fig. 6. x 20 diameters. 
Fig. 7. 7th section of nasal region, x 7-| diameters. 
Fig. 7 s . Mandibular portion of same section. X 7^ diameters. 
