. The elements of Embryology. Embryology. 118 THE THIRD DAY. Ftg. 38. [ Head of a Chick of the Third Day viewed sideways as a Transparent Object. (From Huxloy.) T a. the vesicle of the cerebral hemisphere. I b. the vesicle of the third ventricle (the original fore-brain); at its summit is seen the projection of the pineal gland e. Below this portion of the brain is seen, in optical section, the optic vesicle a already involuted with its thick inner and thinner outer wall (the letter a is placed on the junction of the two, the primary cavity being almost obliterated). In the centre of the
. The elements of Embryology. Embryology. 118 THE THIRD DAY. Ftg. 38. [ Head of a Chick of the Third Day viewed sideways as a Transparent Object. (From Huxloy.) T a. the vesicle of the cerebral hemisphere. I b. the vesicle of the third ventricle (the original fore-brain); at its summit is seen the projection of the pineal gland e. Below this portion of the brain is seen, in optical section, the optic vesicle a already involuted with its thick inner and thinner outer wall (the letter a is placed on the junction of the two, the primary cavity being almost obliterated). In the centre of the vesicle lies the lens, the shaded portion being the expression of its cavity. Below the lens between the two limbs of the horse- shoe is the choroidal fissure. II. the mid-brain. III. the hind-brain. V. the rudiments of the fifth cranial nerve, VII. of the seventh. Below the seventh nerve is seen the auditory vesicle h. The head having been subjected to pressure, the vesicle appears somewhat distorted as If squeezed out of place. The orifice is not yet quite closed up. I, the inferior maxillary process of the first visceral or man- dibular fold. Below, and to the right of this, is seen the first visceral cleft, below that again the second visceral fold (2), and' lower down the third (3) and fourth (4) visceral folds. In front of the folds { to the left) is seen the arterial end of the heart, the aortic arches being biu-ied in their respective visceral folds. f. represents the mesoblast of the base of the brain and spinal Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Foster, M. (Michael), Sir, 1836-1907. London, MacMillan
Size: 1525px × 1638px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookautho, bookcentury1800, bookdecade1880, booksubjectembryology
