This is the largest online encyclopedia, virtual dynamic library equivalent to about 600 volumes. It is an integrated compendium of 21 component encyclopedias.
Working list of all known plant species in collaboration between the Royal Botanic Gardens, Kew and Missouri Botanical Garden. Provides the accepted Latin name, synonyms and rejected forms. (Aims to be comprehensive for vascular plant).
Zoologist Dan-Eric Nilsson of the University of Lund in Sweden explains how the complex human eye could have evolved gradually from a primitive light-sensitive eye-spot.