70 M. F, GUYER AND E. A. SMITH 



element and at least some of its material antecedents in the 

 germ, that they too may be influenced specifically by the serum 

 in question? 



In an attempt to find answers to these and kindred questions, 

 the authors of this paper have undertaken a series of experi- 

 ments to produce specific antenatal effects in fetuses by means 

 of cytolysins; to determine how early in an embryo cytolytic 

 effects may be secured; to obtain cytolysins which will be op- 

 erative in the developmental stages of certain periodically re- 

 newed structures, such as feathers; and particularly, to test the 

 possibility of securing specific effects through the germ itself. 



The present paper concerns itself mainly with the antenatal 

 effects secured in rabbits and mice by means of fowl serum 

 sensitized with lens. Experiments more or less similar to those 

 here recorded are still in hand aiid others are soon to be under- 

 taken on a more extensive scale. 



2. EFFECTS OF LENS CYTOLYSINS ON FETAL RABBITS 



The lenses of rabbits were used as antigen and chickens were 

 employed as the source of the antibodies. The lenses, immedi- 

 ately upon removal from the dead animal, were pulped thor- 

 oughly in a mortar and diluted sufficiently with normal saline 

 solution to permit of injection into the peritoneal cavity of the 

 fowl by means of a hypodermic syringe. In order to prevent 

 injury to internal organs, the fowl was held back downward that 

 the viscera might settle away from the ventral abdominal wall, 

 and the puncture was made just under the tip of the breast bone. 

 At this point the needle enters easily, no internal resistance to the 

 discharge of the liquid from the syringe is encountered and the 

 fowl apparently suffers no pain. 



When the fowl was ready for removal of the serum, killing 

 proved to be more practicable than drawing off blood from the 

 living bird. To secure the blood in sterile condition, the fowl 

 was anaesthetized with ether until insensible, the feathers were 

 hastily plucked from the neck and the latter washed in alcohol, 

 the skin was cut entirely around the neck near the head and 



