638 ZOOLOGY SECT. 



The hypothesis of evolution was also supported by Lamarck's 

 contemporary, Etienne Geoffroy St. Hilaire, who denied use- 

 inheritance and considered the direct action of the environment as 

 the sole cause of transformation. He also differed from Lamarck 

 in believing in the occurrence of sudden changes, e.g., in the 

 possibility of the emergence of a fully-formed Bird from a Reptile's 

 egg. In systematic zoology he established the orders Mono- 

 tremata and Marsupialia : the members of the latter group had 

 hitherto been distributed among Rodents and Primates. 



Another keen supporter of evolution was the great poet Goethe 

 (1739-1832), who also introduced the word Morphology, and made 

 important contributions to the department of science thus named. 

 He propounded the vertebral theory of the skull, presently to be 

 referred to (p. 640), recognised the importance of vestigial organs, 

 and predicted the presence of a premaxilla in Man the absence of 

 that bone in the adult human skull being hithero considered as 

 distinctively separating the genus Homo from the other Primates. 



That the views of Lamarck and the other evolutionists produced 

 so little effect upon contemporary science is largely due to the 

 great and far-reaching influence of Georges Cuvier (1769-1832), 

 one of the greatest of comparative anatomists, whose views 

 dominated zoological science for half a century. He propounded 

 the fruitful principle of correlation, according to which peculiarities 

 in one part of the body are always associated with equally 

 characteristic features in other parts e.g., the ruminating stomach 

 with cloven hoofs. He rejected the idea of a scale of being or 

 unity of type, and, in his great work, the Eegne Animal, abandoning 

 the linear classification, divided animals into four Branches (em- 

 l>ranchemens), each with its own plan of organisation and inde- 

 pendent of the rest. This conception, though not absolutely 

 correct, marked a great advance in classification, as the following 

 table shows. 



Branch 1. VERTEBRATA. 



2. MOLLUSCA [including Tunicata, Brachiopoda, and 

 Cirripedia, as well as the true Mollusca]. 



3. ARTICULATA [including Arthropoda and Annulata]. 



4. RADIATA [including Echinodermata, Polyzoa, Nemat- 

 helminthes, Platyhelminth.es, Ccelenterata, Sponges, 

 and Protozoa. The Rotifera are placed among the 

 Protozoa, and Bacteria and the Pedicellarise of 

 Echinoderms are also included]. 



Here, it will be seen, the Vertebrata as a whole, and not the 

 separate classes of that phylum, are considered as the equivalent 

 of one of the great invertebrate sub-divisions : the Liniia3an 

 Vermes are broken up, Mollusca being elevated to the rank of a 

 primary sub-division, and the articulated worms associated with 



