ORGAN AND BODY SYSTEMS 505 



under ordinary therapeutic usage in sufficient quantity to cause damage, 

 unless very high dosage is used. Transplantation of the kidney or its 

 delivery through an incision for the purpose of irradiation offers the 

 simplest method of producing changes which simulate those due to chronic 

 nephritis, without damage to other organs. The method is cumber- 

 some, but the procedure can be used in the study of this type of nephritis. 



ADRENALS 



These glands have been shown to be highly resistant, and very strong 

 doses must be given to cause the changes which occur chiefly in the 

 cortical portion (71, 362, 369). The complete disappearance of the 

 medullary portion with extensive fibrosis, after direct irradiation, has 

 been reported (210), but Doub, Bollinger, and Hartmann (83, 84) 

 using large doses found only chronic changes, consisting of a thickened 

 capsule, an increase in the lipoid content of the zona glomerulosa, and 

 moderate fibrosis of the cortex. No demonstrable adrenal insufficiency 

 was present. They believe that marked acute damage may occur, but 

 this is not permanent because of the great regenerative power of the 

 gland. Frey found no change whatever except for transient hyperemia 

 and retarded cell division (107). He used only male animals, because in 

 females the unavoidable irradiation of the ovaries introduces complica- 

 tions. He remarks that "the statements in the Uterature as to the direct 

 damage caused by roentgen rays and radium to suprarenals and the 

 great sensitivity of these are not according to fact; it is a question of an 

 indirect and not any direct, specific, or elective effect of the rays." 



This subject is of considerable interest for future research because of 

 the physiological studies which might be made if it were possible to 

 damage certain portions specifically without causing specific damage to 

 other parts. Great technical handicaps must be overcome because of the 

 well-known difficulties with which any physiological study of the adrenals 

 is faced. Much of the older work is of doubtful value. 



EYE 



Roentgen, in 1897, reported that the new rays that he had discovered 

 had a stimulating effect on the retina. The sensation of light, when the 

 eye is irradiated directly, has been attributed to a direct stimulative 

 action on the retina or to the production of fluorescence (302, 346). 



The reactions in the cornea show as plain epithelial damage and a 

 fine stippling 5 days after the irradiation, when the lids and sclera are 

 quite swollen and a slimy secretion is present on the sclera (168). The 

 stipling on the surface soon becomes confluent so that great ulcerative 

 defects invading the corneal substance appear, and a keratosis follows. 

 The iris, the lens, and the background showed nothing pathological in 

 this stage. Larger doses produce on the cornea a confluent ulceration, 

 with the development later of a definite keratitis, lasting about 6 months 



