InJiibitive Action of Roentgen Rays. 195 



While the effect of the Roentgen rays is seen chiefly in the 

 inhibition or alteration of reproductive activity in the cells of 

 animal tissues it is improbable that it is limited to the results 

 of such action. Schaudinn has shown^ that individuals of sev- 

 eral species of protozoa may be killed by exposure to the Roentgen 

 rays for a few hours. Other forms are not, however, thus sus- 

 ceptible.^ 



1 Archiv f. die gesammte Physiologic, LXXVII, p. 29, 1899. 



2 Schwarz in a recent interesting paper (Uber die Wirknng der Radium- 

 strahlen, Archiv. f. die gesammte Physiologic C, 532, 1903) concludes that the 

 action of radium rays is due to a decomposition similar to that of a dry dis- 

 tillation brought about in albunienoid bodies of the cell. He explains their 

 effect on rapidly growing tissues as due to their special power to decompose 

 lecithin. 



