THE SEQUOIA 



result of successive catastrophes), rather than Uniformitarian- 

 ism (the belief that the present condition of the earth has been 

 brought about by a gradual, uniform change). The work of 

 Cuvier in comparative anatomy is also important, and he is 

 called the founder of this science. He recognized the principle 

 of correlated growth, and in " Le Regne Animal" improved the 

 classification of animals. 



The last century of our tree's life was remarkable for the dis- 

 coveries in all branches of natural science. De Blainville (1839- 

 1849) an d Lyell (1797-1875) made valuable contributions to 

 palaeontology and geology. Lyell' s "Principles of Geology" 

 (1830-183 3) dealt a death blow to catastrophism, and is a work 

 second only in importance to the " Origin of Species." 



Milne-Edwards (1800-18 18) enunciated the principle of the 

 physiological division of labor. 



Von Baer (1828) announced the law that bears his name, 

 namely, ' ' individual development is a recapitulation of race 

 development." 



Schleiden and Schwann (183 8- 1839) discovered cells in plants 

 and animals, and propounded the cell theory. 



Valentin (1839) named the "nucleus," and was the first to 

 speak of the " cell theory." 



Purkinjeandvon Mohl (1840) named the substance of the cell 

 protoplasm. 



Serres (1842) asserted that all missing links would be found 

 in embryology. 



De Barry (1843) observed the union of sperm and ovum. 



Kolliker (1846) demonstrated that sperm are developed from 

 the tissues of the testes. 



Owen (1846) pointed out the difference between homologous 

 organs, for example, the arm of man, fore limb of horse, and wing 

 of bird, organs which are formed on the same structural plan, 

 and analogous organs, for example, wing of bird and wing of 

 butterfly, organs differing entirely in structure, but performing 

 the same function. 



Remak (1850) described "three germinal layers," and Huxley 

 (1859) homologizes them in the lower animals. 



