Tree tissue. It protects the trunk against the elements, disease, animal attack and fire. It is perforated by a large number of fine breathing pores called lenticels, through which oxygen diffuses. Bark is continually replaced by a living layer of cells called the cork cambium or phellogen. The London plane ("Platanus × acerifolia") periodically sheds its bark in large flakes. Similarly, the bark of the silver birch ("Betula pendula") peels off in strips. As the tree's girth expands, newer layers of bark are larger in circumference, and the older layers develop fissures in many species. In some trees such as the
White-winged vampire bat White-winged vampire bat The white-winged vampire bat ("Diaemus youngi"), a species of vampire bat, is the only member of the genus Diaemus. They are found from Mexico to northern Argentina and are present on the islands of Trinidad and Margarita. The white-winged vampire bat was described by Dutch zoologist Fredericus Anna Jentink in 1893. Dr. Charles Grove Young (1849-1934) is the eponym for the species name "youngi". Jentink decided to honor Young with the species name because "our Museum is indebted [to him] for so many additions to its collections of the British Guyana animals." When it was described by