CHAPTEK X. 



GENEOLOGICAI* 

 GENEOLOGY. 



A TEBM is needed for the study of living crea- 

 tures in their time-relations, for the enquiry into 

 their individual development, racial evolution, and 

 historical aspects generally; and we have suggested 

 the term genealogy (changing a letter in the narrower 

 word genealogy). This "science of becoming" 

 would include (a) individual development, growth, 

 and life-history (ontogeny) ; (6) the racial history 

 (phylogeny) ; (c) the relation of genetic continuity 

 between successive generations (heredity). 



DEVELOPMENT OF THE INDIVIDUAL. 



Beginnings of Embryology. Embryology is en- 

 tirely a modern science. Though Aristotle watched 

 the heart-beats of the unhatched chick, and had hold 

 of the idea that development is a progressive differ- 

 entiation and not an unfolding of preformed parts, 

 he had practically no successors before Harvey 

 (1578-1675). 



William Harvey. With the aid of magnifying 



