The 24th of November marks the 150th anniversary of the publication of Darwin’s defining work, On the Origin of Species. You can find the complete Origin, as well as all other works by Darwin, online here.
Just prior to publishing The Origin, Darwin published books about both fossil and extant forms of what was surely his favorite arthropod; the barnacle. Barnacles are sessile crustaceans, within the cirripedian infraclass. Learn more about Darwin’s work on barnacles and how they helped shape his theory of evolution, here.