Red blood cell being dissolved in body fluid) was an important step in the evolution of vertebrates as it allows for less viscous blood, higher concentrations of oxygen, and better diffusion of oxygen from the blood to the tissues. The size of red blood cells varies widely among vertebrate species; red blood cell width is on average about 25% larger than capillary diameter, and it has been hypothesized that this improves the oxygen transfer from red blood cells to tissues. The red blood cells of mammals are typically shaped as biconcave disks: flattened and depressed in the center, with a dumbbell-shaped cross section,
Red as Blood, or Tales from the Sisters Grimmer Red as Blood, or Tales from the Sisters Grimmer Red as Blood, or Tales from the Sisters Grimmer is a short story collection of dark fantasy retellings of popular fairytales by British author Tanith Lee. Contrary to what the title may suggest, it not only includes retellings of fairytales by the Brothers Grimm, but also by Charles Perrault, Gabrielle-Suzanne Barbot de Villeneuve or Alexander Afanasyev. The title story was nominated for a Nebula Award. "Red as Blood, or Tales from the Sisters Grimmer" contains the following tales: In 2014, the book was released as an expanded edition including a new