LIXNEAN SOCIETV OF LONBOX. 4 1 



Dai'wiii.' For genenil biolo;^if;il clsssificatioii it inaugurated a 

 new epoch, and Huxley described it as "one of tlie greatest 

 scientilic works ever ])ublished." In this work he repeated!}' 

 insists on the importance of the " I'lmdamental Biogenetic Law," 

 which may be briefly stated in liis own words, " Ontogeny repeats 

 Phylogeny."' Tlie book ditl not attract much attention from the 

 general public, so lie wrote a resume of a part of it in popular 

 form under the title of' Natiirliche fcjchopfungsgesciiichte,' and it 

 was a great success. It naturally brought storms about his head,, 

 but it also brought him a following apart from that formed by 

 his scientific friends and pupils. An English translation under 

 the editorship of Sir E. E;iy Lankester iijjpeared in 1870, inider 

 the title of ' The History of Creation.' 



In 1866 Haeckel went to the Canaries, visiting England and 

 Darwin at Down on the way. There he worked at the Medusa?,, 

 aiul especi;illy the Siplionophores. It was during this visit that 

 he became uiterestetl in Sponges, but it was not until 187:i 

 that his great monograph on tlie Calcispongise was published. 

 Ill this he formulated his Gastraea-theory, which was really a 

 special ap])lication of the Biogenetic law. \vl subsequent years 

 he elaborated his studies on the Gastra^a, and published them in 

 one book in 1877. 



In 1867 he married Agnes Huschke, the daugliter of the 

 distinguished anatomist at Jena. They had tliree children, a son 

 who became an artist, and two daughters. 



Another large treatise appeared in 1874 under the title of 

 ' Anthropogenic,' and in it Haeckel applied his fundamental 

 Biogenetic law to the evolution of Man. The book is in two 

 parts ; the first being on Ontogeny, practically a philosophical text- 

 book on Human Embryology, while in the second part Phylogeny 

 treats of the foundations of Anthropology. (The 5th Edition was 

 translated into English under the title of 'Tiie Evolution of Man,' 

 1905.) After giving an account of the evolution of (he various 

 tissues and organs of Man's body, he goes on to the evolution of 

 Man's soul, the psychic organ being the brain. " The human soul 

 or psyche, as a function of the medullary tube, has developed 

 along with it ; and just as brain and spinal cord now develop from 

 the simple medullary tube in everj'- human individual, so the 

 human mind or the psychic life of the whole human race has 

 been gradually evolved from the lower vertebrate soul." Logically, 

 therefore, both proceed from the very ])rimitive soul of" Man's 

 Protozoon ancestors. In 1876 he published a short essay, ' Die 

 Perigenesis der Plasfidule.' This is one of his most remarkable 

 pieces of work. Hering in 187') had shown that memory must 

 be considered a general function of organic matter, and that 

 reproduction and inheritance can only be ex])lained by admitting 

 the existence of this unct)nscious memory. In the above men- 

 tioued essay Haeckel elaborated this idea. He resolved cells into 

 plastidules (molecules), and applied the physical ))rinciple of 

 transmitted motion to them. In his own words : "I concluded 



