lii THE ANIMAL KINGDOM. 



here and there, and given us a theory well grounded on facts. It was reserved, liow- 

 ever, for the tireless genius of Darwin, with his masterly handling of facts, to impress 

 his conclusions on the age, supporting them as he did with an overwhelming array of 

 facts. His compactly built superstructure was erected on a temporary foundation, 

 which it will be the work of the future to rebuild with solid masonry, i-esulting from cen- 

 turies of labor in the field first pointed out by Lamarck. The influence of Lamarck's 

 work was feeble, owing to the strong counter-currents set up by Cuvier, Agassiz, and 

 popular prejudice. 



What Lamarck actually accomplished has been restated by Charles Martins. He 

 noticed the variations of species, both of animals and plants. The best results of 

 his labors of over thirty years in botany, and afterwards of thirty years in zoology, 

 were his division of the animal kingdom into vertebrates and invertebrates; his 

 founding the classes of Infusoria and of Arachnida ; his separation of the Cirripedia 

 from the Mollusca, only a few years before Thompson discovered their true affinities. 

 Lamarck had a powerful imagination, and was a born speculator ; but the age in which he 

 worked was barren of facts, and many of his theories were ill-founded. The grand results 

 of his work were clear views as to the unity of organization of the animal kingdom, 

 the filiation of all animal forms, and the influence of external agencies on the varia- 

 tion of species ; he recognized the effects of use and disuse on the development and 

 atrophy of organs ; he recognized the agency of the water, of air, of light, of heat, in 

 bringing about changes in organisms ; finally, Lamarck was the first to construct a 

 phylogeny or genealogical tree of animals. 



Lamarck's doctrine of appetency was carried too far, and exposed his ^•iews in 

 general to ridicule; he maintained that spontaneous generation takes place at the 

 present time; others have advocated this doctrine since Lamarck, and only within a 

 few years have the researches of Tyndall led him and Huxley, as well as others, to 

 affirm that there is no evidence that the process is now going on. 



In his famous coiitroversies with Cuvier, Geoffrey St. Hilaire stated his belief in the 

 modification of sioecies by changes in the conditions of life. As successors in Europe 

 may be mentioned the following writers : Wagner, Martins, and Plateau, as well as 

 those given below. . 



In Germany, the distinguished anatomist, histologist and embryologist, Kolliker, 

 in his 'Morphology and developmental History of Pennatulids,' published in 1872, con- 

 cludes as follows : " Such external forces have operated so as to modify, in many 

 ways, developmental processes, and no theory of descent is complete which does not 

 take these relations into account. Manifold external conditions, when they operate on 

 eggs undergoing their normal development, on larvae and other early stages of animals, 

 and on the adult forms, have produced in them partly progressive, partly regressive, 

 transformations. ... Of such external forces the most important are the mode of life 

 (parasitic and free-living animals, land and water animals), nutrition, light, and heat." 



In his History of Creation (1873), Haeckel gives full credit to Lamarck's views, say- 

 ing : " Without the doctrine of filiation, the fact of organic development in general 

 cannot be understood. We should, therefore, for this reason alone, be forced to 

 accept Lamarck's theory of descent, even if we did not possess Darwin's theory of 

 selection." Here may also be mentioned the researches of Siebold and of Brauer, on 

 the effects of desiccation on the eggs of phyllopod Crustacea, and of Hogg, Dumeril, 

 Wyman, and others, that the metamorphosis of frogs is hastened or retarded by differ- 

 ences in temperature and light. 



