xvi THE HISTORY OF ZOOLOGY 657 



The hypothesis of evolution was also supported by Lamarck's 

 contemporary, Etienne Geoffrey St. Hilaire, who denied 

 use-inheritance and considered the direct action of the environ- 

 ment 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 

 Monotremata 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. 659), 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 hitherto 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 char- 

 acteristic 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 Regne Animal, abandoning 

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

 branchements), each with its own plan of organisation and in- 

 dependent of the rest. This conception, though not absolutely 

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

 table shows. 



Branch 1. VERTEBRATA. 



2. MOLLUSC A [including Tunicata, Brachiopoda, and 



Cirripedia, as well as the true Mollusca]. 

 3. ARTICULATA [including Arthropoda and Annulata]. 

 4. R ADI ATA [including Echinodermata, Polyzoa, Nemat- 

 helminthes, Platyhelminthes, 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 Linnsean 

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



