..., 0.125±0.005 mm). Vascular density index(VDI), a stereological index that is affected by both vessel number and length, is greatest in –Hb C. aceratus (3.51±0.20) and lowest in +Hb N. coriiceps (1.58±0.14). Among four +Hb species, there is a direct relationship between red blood cell content and retinal...

... 1993 © 1993 by Company of Biologists 1993 reptile bird chorioallantois vascular density gas exchange chicken Gallus gallus quail Coturnix coturnix turtle Chelydra serpentina A major determinant of the rate of diffusive exchange of gases in animals is the morphology...

..., there is no comparative information about the chorioallantoic membrane. Given the differences in size and phylogeny, it might be expected that significant morphological differences exist in this gas-exchange organ. The vascular density index was determined following procedures similar to those of Dusseau and Hutchins...