. The development of the chick : an introduction to embryology. Embryology; Chickens -- Embryos. 298 THE DEVELOPMENT OF THE CHICK which the two tubo-tympanic cavities open. The median cham- ber communicates by a longitudinal slit (tubal fissure) in the roof of the pharynx with the oral cavity (Figs. 168 and 175). The frontal partition in question is a posterior pro- longation of the palatine processes of the maxillary arch, and forms as follows: If the head of a four-day chick be halved by a sagit- tal plane, and the interior of the pharynx and mouth cavity be then viewed by reflected light, a
. The development of the chick : an introduction to embryology. Embryology; Chickens -- Embryos. 298 THE DEVELOPMENT OF THE CHICK which the two tubo-tympanic cavities open. The median cham- ber communicates by a longitudinal slit (tubal fissure) in the roof of the pharynx with the oral cavity (Figs. 168 and 175). The frontal partition in question is a posterior pro- longation of the palatine processes of the maxillary arch, and forms as follows: If the head of a four-day chick be halved by a sagit- tal plane, and the interior of the pharynx and mouth cavity be then viewed by reflected light, an elongated lobe will be seen on the me- dian surface of the mandib- ular arch and maxillary process (Fig. 174 A). This lobe begins far forward on the median surface of the maxillary process and may be followed posteriorly over the median surface of the mandibular arch to the first visceral pouch, where it ends with a free rounded B Fig. 174. — A, Head of a chick embryo of 4 days, halved by median section and viewed from the cut surface. (After extremity. The lobe itself Moldenhauer.) B. Internal view of the pharynx of a pigeon embryo, corresponding in develop- ment to a chick of 10 days. (After Mol- denhauer.) Col. 1., Colliculus lingualis. Col. p. p., Colliculus palato-pharyngeus. Cr. i., Crus inferior. Cr. s., Crus superius. Hyp., Hypophysis. Mx., Maxilla. N'ch., No- tochord. O. Ph. T., Ostium tubae phar- yngse. S. P., Seessell's pocket. 2, 3, 4, Second, third, and fourth visceral arches. is called by Moldenhauer the colliculus palato-phar- yngeus; it is bounded above and below by depressions, viz., the sulcus tubo-tym- panicus dorsally and the sulcus lingualis ventrally, both of which end behind in the first visceral pouch; anteriorly the ventral furrow disappears at the margin of the mouth, and the dorsal furrow near SeessePs pocket. The maxil-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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Keywords: ., bookauthorlilliefrankrat, bookcentury1900, booksubjectembryology
