82 M. F. GUYER AND E. A. SMITH 



observable in any of the injected females. A possible explana- 

 tion of the lack of effect on the mothers may be that, because 

 of meager circulation of blood in the lenses of adults, the quan- 

 tity of cytolytic serum which reaches a lens is insufficient to 

 affect it. In the developing eye of the young, the circulation is 

 probably much fuller. The lenses in such forms, moreover, are 

 in the process of formation and are not the fibrous masses which 

 exist in older animals. For these reasons the lenses of immature 

 animals are probably more susceptible to cytolytic and kindred 

 agents. 



The fact of chief interest is that visible specific structural 

 modifications can be engendered in the young in utero by means 

 of specifically sensitized serum. The present paper is to be 

 regarded as a report of progress in a more extensive series of 

 experiments. 



