STUDIES ON CYTOLYSINS 



71 



peeled back, the oesophagu.s and trachea were transected and 

 turned back so as not to discharge into the receptacle for catch- 

 ing blood, the head was then quickly severed near its base with 

 heavy scissors and the neck thrust into a wide-mouthed sterile 

 test-tube or flask. 



Blood removed in this way was chilled in the dark for one or 

 more hours and then centrifuged for some twenty minutes to 

 separate the serum from the clot. The serum so obtained was, 

 after warming to blood heat, injected into rabbits through the 



* All rabbits half grown. 



marginal vein of the ear. All operations including those per- 

 formed on rabbits were done with sterilized instruments and 

 vessels and under as aseptic conditions as possible. 



Experiment 1 



In this experiment four fowls eight months old were used for sensi- 

 tizing with lens material, and two pregnant rabbits, each of which had 

 previously born normal litters, were the recipients of the sensitized 

 fowl serum. 



On November 1, 8, 15, and 22, respectively, the four fowls were in- 

 jected intraperitoneally, each time with. the lenses from an adult rab- 

 bit (table 1). The lenses were pulped and diluted with 6 to 8 cc. of 



