676 VERHOEFF AND BELL. 



it is certain that repair of the injury to the lens epithelium takes 

 place largely without the aid of this process. This is proved by the 

 fact that mitosis does not occur in tlie severely injured cells, that is 

 in the cells containing granules. Each of these cells, therefore, if it 

 imdergoes recovery as usually is the case, must do so without indirect 

 division. It is evident that the eosinophilic and basophilic granules 

 finally' become dissolved out. The enlargement, direct division, and 

 budding of many of the nuclei probably represent the response of 

 the latter in the process of cell repair. Similar nuclear changes are 

 sometimes seen in malignant tumors. The nuclear buds are still 

 present at the end of two months and their ultimate fate is prob- 

 lematical. 



Finally the question arises whether or not the cell changes de- 

 scribed are characteristic only of the action of abiotic radiation. As 

 will be pointed out later, experiments on the cornea prove that the 

 basophilic and eosinophilic granules are not produced by heat, and 

 thus their occurrence in cells constitutes a distinct difference between 

 heat and abiotic effects. On the other hand, the following experi- 

 ment proves that the same cell picture may be produced by chemical 

 agents. A few drops of Lugol's solution containing 25% iodine were 

 injected into the anterior chamber of a rabbit's eye. The injected 

 fluid became mostly precipitated so that its action on the lens surface 

 was not uniform. On examining the lens capsule 24 hours later 

 there were found, in addition to more extreme changes, areas in 

 which the cells showed identically the same changes, including the 

 basophilic and eosinophilic granules as are produced by the action 

 of abiotic radiation. It is therefore obvious that these changes are 

 not characteristic of abiotic action alone, but may be produced by 

 other forms of chemical action as well. It is interesting that in this 

 experiment, as previously mentioned, a wall was formed similar to 

 that produced l)y abiotic rays, evidently due to the pressure of the 

 injured cells within the pupillary area on the peripheral cells which 

 were protected from injury by the contact of the iris with the lens 

 (PI. 3, Fig. 10). 



The changes just described occurring in the lens capsule after expo- 

 sure to abiotic rays, are essentially the same as those described by 

 Hess ^^^ who used much longer exposures but a light source of much 

 less intensity than employed by us. Hess does not describe the 

 granules in the cytoplasm, although they are shown well in his excel- 

 lent illustrations. He also does not describe direct division and 

 budding of the nuclei, although the latter process likewise seems to be 



