6 



THE AMEBIC AX NATURALIST 



[Vol. XLV 



depend the chemico-physical relations of tissue compo- 

 nents and structures of all kinds. If physiology escapes 

 the soporific and deadening influence of the vitalistic con- 

 ceptions, now appearing in some profusion, it may in turn 

 furnish the secure means for a long and rapid advance 

 in genetics, and it may be assumed with some certainty 

 that the chief superstructures of evolutionary science will 

 be those securely raised upon a foundation of physiolog- 

 ically tested facts. 



In taking this direction, natural history is not alone ; 

 the briefest comprehensive view of the physical sciences 

 will show that here also the chief advance lies along the 

 way of the study of energetics, and that the fundamental 

 problems are those lying about the mode and means of 

 transformations of energy. 



Recent events in the held of evolution comprehend a 

 number of movements and accomplishments of extraor- 

 dinary interest. The rediscovery of the facts of alter- 

 native inheritance, the formulation of the concepts of 

 equivalent, balanced, paired or differential characters, the 

 results of statistical studies of variability, the analyses 

 of species of various constitution by pedigree cultures, in 

 which the value of fertilization from various sources is 

 carefully measured, the distinction of the biotype or geno- 

 type as a hereditary entity, the possibilities in the ac- 

 tion of pure lines within a specific group, the cytological 

 contributions of fact and forecast upon the physical as- 

 pects of heredity, and lastly the presentation of the facts 

 and allowable generalizations identified with the muta- 

 tion theory, comprise a series of advances, of accretions 

 to knowledge, furnish n broadened foundation for biolog- 

 ical science, and disclose additional possibilities in all lines 

 of experimental research with living things, besides open- 



work of Charles Darwin, by more than fourscore workers 



