EXPERIMENTAL BIOLOGY 



587 



The Vienna institution differs from most of the preceding biological 

 institutes in that here experimentation, carried on for long periods of 

 time, even generation after generation, if necessar}', and always under 

 the best possible conditions, takes the place of research in descriptive 

 and comparative anatomy, or the briefer experiments of physiology. 

 In the study of experimental evolution one not only follows the organ- 

 isms through ovulation, fertilization and embryogenesis, but the new 

 generation must be raised to the adult stage for another breeding. The 

 laws through which the external factors of existence influence the 

 vitality can only be determined when it is possible for the organisms 



Fig. 4. Hocse foe Higher Vertebrates. 



experimented on to live under unchanging conditions for months or 

 even years. Darwin acted upon these principles and his garden at 

 Down must always rank as one of the greatest laboratories for experi- 

 mental biology. It is only necessary to visit the zoological institute in 

 Wtirzburg with its vivaria, series of basins and shaded pond, to realize, 

 as one can from his writings, that Semper also was fully aware of the 

 primary importance of experimentation in the solution of biological 

 problems. Along with the foundation and growth of the Vienna insti- 

 tution has been that of the station for experimental evolution of the 

 Carnegie Institution created and directed by Davenport, and the gar- 

 dens developed by Ewart and Bateson in Great Britain. Similar es- 

 tablishments for the study of genetics have been advocated by Behla 

 (1894), and more recently by Plate (1906) and Miiller (1907). In- 



