THE GERM-PLASM THEORY 263 



a criterion by which may be tested the truth of theories 

 based upon the interpretation of minute phenomena 

 only made visible by the highest powers of the micro- 

 scope. The disinterment of Mendel's discovery took 

 place only six years ago ; and the rapid manner in 

 which the facts of cytology have been found to fall 

 into line with Mendelian conceptions augurs well for 

 the future progress of discovery in these fields. 



