Walter Gaskell, a Cambridge physiologist famous for his work on the heart and nervous system, sets out a bold theory: that vertebrates arose from an arthropod ancestor resembling the king crab Limulus and the ancient sea scorpions. Chapter by chapter he compares nerves, muscles, gills and organs in lampreys, crustaceans and fossil forms to support it.
A major, now rejected evolutionary hypothesis argued in depth, for historians of biology. Download the free EPUB.