SUSCEPTIBILITY OF AMPHIBIAN OVA TO X-RAYS 429 



Sweat glands are much more insusceptible to the rays than the 

 sebaceous glands, but improvement in some cases of hyperidrosis 

 has been reported after exposure to the X rays. (Pusey ) The 

 action of the rays in these cases is not clear since it seems improb- 

 able that atrophy of the sweat glands could be caused without 

 resorting to exposures severe enough to injure seriously the epi- 

 dermis. 



Beneficial treatment of malignant growths seems to be due 

 chiefly to interference with cell multiplication and a consequent 

 retrograde metamorphosis. In some carcinomata the cancer 

 cells are evidently more susceptible to the X rays than the nor- 

 mal epidermis is. This susceptibility is apparently to be ascribed 

 to interference with the anabolism of genetic, probably nuclear 

 material. The question as to whether cancers exhibiting a con- 

 siderable degree of differential morphogenesis are more suscept- 

 ible than those characterized by a comparatively simple multi- 

 plication of like cells has not, so far as I am aware, been carefully 

 studied. There is usually, however, some degree of differential 

 morphogenesis in cancers. In sarcomata this is usually less 

 marked and sarcomata seen to be frequently less susceptible to 

 the rays than carcinomata. It is now well established that the 

 differential morphogenesis of the normal epithelium may be 

 occasionally so distributed by the repeated exposure to the X rays 

 as to cause the production of carcinomata. 



The beneficial effect of X ray treatment in other than malig- 

 nant growths may be due in part to a tonic stimulative irritation 

 which moderate exposure to the rays may give rise and in part 

 to inhibition of abnormal reproductive activity in the inflamed 

 tissues, or to the destruction of tissues of low resistance. It does 

 not seem to be due to any considerable extent to direct action of 

 the rays on the organisms which give rise to the inflammation. 

 The nature of the anodyne effects of the rays is not understood. 

 The clinical use of the X rays in the treatment of diseases of the 

 blood seems to depend upon the action of these rays on the pro- 

 duction of blood corpuscles. 



It is possible that both X rays and radium might have a favor- 

 able effect on development if carefully regulated in intensity. 



