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Full-Text Articles in Life Sciences
Buoyancy Changes As Related To Respiratory Behavior In An Amphibious Snail, Pomacea Urceus (Müller), From Venezuela, Kathleen A. Burky, Albert J. Burky
Buoyancy Changes As Related To Respiratory Behavior In An Amphibious Snail, Pomacea Urceus (Müller), From Venezuela, Kathleen A. Burky, Albert J. Burky
Biology Faculty Publications
The ampullariid Pomacea urceus uses its ctenidium and lung in respiration. The snails reach the surface with their siphon and ventilate their lung by withdrawing their head-foot in a pumping action. The lung gas also serves to change the buoyancy of the snails. After a ventilation a snail does not necessarily return to the same buoyancy level. They may achieve overall specific gravities of <1 to > 1 after a ventilation. They may remain submerged (s.g. > 1) or float (s.g.
Comparative Anatomy And Systematics Of Picrodendron, Genus Incertae Sedis, W. John Hayden
Comparative Anatomy And Systematics Of Picrodendron, Genus Incertae Sedis, W. John Hayden
Biology Faculty Publications
This study of the vegetative anatomy of Picrodendron and some of its putative relatives has been undertaken in order better to understand its natural relationships. Despite the number of anatomical studies in the literature (Jadin, 1901; Solereder, 1908; Boas, 1913; Webber, 1936; Heimsch, 1942; Record & Hess, 1943; Metcalfe & Chalk, 1950), our information on the anatomy of Picrodendron is still incomplete· for example, nodal and petiolar anatomy has apparently never been described. Furthermore, with the exception of Record and Hess (1943), who discussed Picrodendron in a family by itself, other anatomists have compared Picrodendron only with members of Simaroubaceae, …