EXPERIMENTS WITH RADIUM 103 



Now a clear examination of the bodies produced 

 by the action of radium on culture media will 

 enable us to decide under which of these two 

 heads these bodies come. 



Plate I. does not reveal any structure, but 

 Plate II. distinctly shows the existence of a nucleus 

 of a highly organised body, whUst later, in Plate III., 

 the particular segregation effects of growth and 

 development, which it would appear rule crystals 

 out of court, is evidenced. 



This subdivision is the most striking thing about 

 them, and a clear idea of its actual nature cannot 

 be derived fully from the photographs. When 

 the size of the body exceeds this there is a ten- 

 dency for it to divide up as in Plate IV., and 

 to lead a separate existence. 



These products of radio-active bodies thus mani- 

 fest not merely instability and decay but growth, 

 subdivision, reproduction, and, as it were, adjust- 

 ment of their internal functions to their sur- 

 roundings ; a circumstance which may be found 

 to be equivalent to nutrition. Whether we are to 

 regard these products, strictly speaking, as living 

 things is the point which remains to be decided. 

 We have to define their properties as we have 

 defined life. 



Thus by the action of radium upon sterilised 

 bouillon microscopic bodies appear, of which the 

 micro-plates give a clear and a definite idea. 



In the first instance they are not, as micro- 

 organisms would be, of the same size so long as 



