BIOLOGY 



from comparatively simple beginnings is conclu- 

 sive, though the modus operandt remains much 

 in dispute. Natural selection, though no one 

 doubts its general efficiency as a controlling agent, 

 is no longer regarded by most biologists as the 

 universal explanation that some of Darwin's im- 

 mediate followers tried to make of it. Weis- 

 mannism has almost sunk beneath the weight of 

 its cumbersome machinery. Lamarckism, on the 

 other hand, has long been tentatively lifting its 

 head above the troubled w r aters, and if once the 

 difficulty about the inheritance of acquired charac- 

 ters can be satisfactorily disposed of we may expect 

 to see the great French philosopher at length 

 coming into his own. 



In one direction the theory of Organic Evolu- 

 tion has made noteworthy progress in recent 

 years, and that is in connection with the much 

 disputed problem of the origin of living things. 

 The curious attempts to people the earth by means 

 of casual immigrants from other planets, either 

 carried by meteorites or in the form of ultramicro- 

 scopic * cosmozoa ' propelled hither by the vis a 

 tergo of the sun's rays, are being superseded by 

 the idea of extending backwards the process of 

 evolution from the organic to the inorganic world 

 without any break of continuity. The study of 

 the chemical evolution of the carbon compounds, 

 and the possibilities of their synthesis in the 



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