Collection of important essays. Ernst Heinrich Philipp August Haeckel (1834-1919), also written von Haeckel, was an eminent German biologist, naturalist, philosopher, physician, professor and artist who discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms, and coined many terms in biology, including phylum, phylogeny, ecology and the kingdom Protista. Haeckel promoted and popularised Charles Darwin's work in Germany and developed the controversial recapitulation theory. Sir John Arthur Thomson (1861-1933) was a Scottish naturalist who authored several notable books and was an expert on soft corals. He taught at University of Aberdeen from 1899 until 1930, the year he was knighted. His popular works sought to reconcile science and religion. Thomson's Outline of Science, published in 1922, sold more than one hundred thousand copies in five years. Friedrich Leopold August Weismann (1834-1914) was a German biologist. He was ranked the second most notable evolutionary theorist of the 19th century, after Charles Darwin. He graduated as a medical doctor and settled in Frankfurt. During the war between Austria, France and Italy in 1859, he became Chief Medical Officer in the military.
Ernst Heinrich Philipp August Haeckel (February 16, 1834 – August 9, 1919), also written von Haeckel, was an eminent German biologist, naturalist, philosopher, physician, professor and artist who discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms, and coined many terms in biology, including anthropogeny, ecology, phylum, phylogeny, stem cell, and the kingdom Protista. Haeckel promoted and popularized Charles Darwin's work in Germany and developed the controversial recapitulation theory ("ontogeny recapitulates phylogeny") claiming that an individual organism's biological development, or ontogeny, parallels and summarizes its species' evolutionary development, or phylogeny.
The published artwork of Haeckel includes over 100 detailed, multi-colour illustrations of animals and sea creatures (see: Kunstformen der Natur, "Art Forms of Nature"). As a philosopher, Ernst Haeckel wrote Die Welträtsel (1895–1899, in English, The Riddle of the Universe, 1901), the genesis for the term "world riddle" (Welträtsel); and Freedom in Science and Teaching to support teaching evolution.
This is certainly a wealth of information on how the theory of evolution affected and influenced other sciences and religion in the late 19th century. Its a good place to start your understanding of modern theoretical scientific theory.