. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. 638 ANATOMY OF VERTEBRATES. 449 in the embryo Seqient: c is the leathery and partially calcified egg-shell. An embryo Lizard, at an earlier period of develope- ment, is shown in fig. Hunter left the following preparations illustrative of the developement of the Cro- codile. No. 3364 shows the calcareous outer crust of the inner 'membrana puta- minis' of the egg : No. 3365 shows the attachment of the vascular allantoisto that shell membrane in an embryo in wliich part of the yolk has been received within the abdomen
. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. 638 ANATOMY OF VERTEBRATES. 449 in the embryo Seqient: c is the leathery and partially calcified egg-shell. An embryo Lizard, at an earlier period of develope- ment, is shown in fig. Hunter left the following preparations illustrative of the developement of the Cro- codile. No. 3364 shows the calcareous outer crust of the inner 'membrana puta- minis' of the egg : No. 3365 shows the attachment of the vascular allantoisto that shell membrane in an embryo in wliich part of the yolk has been received within the abdomen. In No. 3366 the hinder half of the Crocodile is dissected to show the condition of the vitelline and allantoic sacs at the close of foetal develojie- ment: the vitellicle presents an irregular lobated form, and its short and narrow duct communicates with the small intestine a little below the duodenum: the allantois communicates with the lower and fore part of the cloaca by means of a long and slender duct homologous with the urachus : but no part is dilated, as in certain Lizards, to form the urinary bladder. In No. 3370 is sliown the vitellicle, after inclusion within the abdominal walls ; it is much reduced in size, and its contents are hard and stringy. The period of external incubation hj the action of the sun's rays upon the sand-nest of the eggs of tlic Turtle {ChcJonc Midas) has been ascertained to be seven weeks. Figure 450 shows the embryo of a Snajiping Turtle (Chch/dra siTjinifinn) from an egg laid June 21st and opened Sc]>fenibcr 21st of the same year. The anniios Is cut away: c shows the' area vascu-. Egg anr] unibryo of (he Jloiiitoi- T,izard. xliii. 450. 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 Owen, Richard, 1804-1892; Cornell University. College of Veterinary Medicine. Flower-Sp
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