. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 322 REPTILIA. traordinary and apparently unnecessary length of its canal. In the upper part of its course, the walls of the oviduct secrete the albumen, in which the yoke becomes enveloped, and subsequently the membrana putaminis and the egg-shell are supplied by its inferior por- tions. In correspondence with these changes of function, its lining membrane is found to dif- fer in appearance and structure in different re- gions of the oviduct. Towards the commence- ment of that canal (Jig. 65, p), it is exceedingly Fig. 2
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 322 REPTILIA. traordinary and apparently unnecessary length of its canal. In the upper part of its course, the walls of the oviduct secrete the albumen, in which the yoke becomes enveloped, and subsequently the membrana putaminis and the egg-shell are supplied by its inferior por- tions. In correspondence with these changes of function, its lining membrane is found to dif- fer in appearance and structure in different re- gions of the oviduct. Towards the commence- ment of that canal (Jig. 65, p), it is exceedingly Fig. Oviduct of Emys Europmis. (After Bojanus.) A", commencement of oviduct; nop, canal of oviduct laid open; s t, ovum contained in lower part of oviduct, broken to show the yolk, the albu- men, and the egg-shell; B, allantoid bladder; c n, kidney; E, ureter; F, oviduct; ?/, termination of oviduct; m, termination of the opposite oviduct laid open. delicate, gathered into longitudinal folds, and covered with vibratile cilia lower down (o); the walls of the oviduct become evidently glandular, and towards its termination («), where the outer investments of the egg are secreted, it is thrown into broad irregular ruga;, which are continued as far as its termination in the cloaca (»;)• External to the mucous membrane, there is a stratum of muscular fibres, by the contractions of which the ovum is propelled along the oviduct; and externally it is invested with a peritoneal tunic that ex- tends throughout its whole length. The oviducts in the reptilia are very exten- sible, and in many genera are constructed to contain numerous ova at the same time, as for example in lizards (fig. 240, <?)• ^n se1'" pents, owing to the slenderness of their bodies, the numerous ova thus contained in the ovi- duct are arranged in a very remarkable manner: those lodged in the right oviduct correspond with an unoccupied space in the left, and vice versa those in the left are lodged in
Size: 1260px × 1983px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjectphysiology, booksubjectzoology
