1915] Influence of Radium Eays 151 



The investigators in the second group studied the effect 

 of the radium rays' upon the different tissues of the more or 

 less advanced organism. Seklin, Birch-Hirschfeld, Werner, 

 Heinecke and Thies, Ragaud and Dubreuil, Bergonie and 

 Tribondeau, Aubertin, Delamare and Beaujord, Guyot, 

 Schumann, Lidenborn, and London are some of the work- 

 ers in this field. They found that all tissues are sensitive to 

 radium ra.js, but to a varying degree. In general cells ap- 

 pear to be sensitive to radium according as they have the 

 character of germ cells and have the tendency to increase 

 through rapid cell division. Two kinds of tissues are par- 

 ticularly aif ected : ( 1 ) male and female gonads with the eggs 

 and sperm; (2) blood and lymph with the related spleen, 

 lymph glands, etc. The chromatin of the cell nucleus is 

 affected injuriously and finally the nucleus will be destroyed. 

 As a result of the discoveries of the workers in this field Ront- 

 gen and radium rays have found an application in the treat- 

 ment of rapidly growing structures, such as cancers and 

 tumors. 



As previously stated, the study of the action of radium 

 has been pushed for the past few years by Oskar Hertwig, 

 director of the Anatomical-Biological Institute of the Uni- 

 versity of Berlin. In 1909 he began and has since continued 

 a series of experiments on the influence of radium rays on 

 the development of amphibian embryos. He ran two series 

 of experiments. In his A-series fertilized frog eggs were 

 irradiated for various lengths of time, from five minutes to 

 four hours. Only those eggs radiated for a short time (5-15 

 minutes) developed beyond the very early stages. Those 

 subjected to a longer or stronger radiation did not pass be- 

 yond the blastula stage, where they died. 



The B-series consisted of experiments in which sound 

 eggs were fertilized with sperm radiated for various lengths 

 of time from five minutes to twelve hours. He obtained a 

 great variety of abnormalities which have considerable bear- 

 ing on general embryological theories. We shall not consider 

 that side of his results, however, but shall confine ourselves 



