SPECIFIC AND NONSPECIFIC RESISTANCE 



mouse; just put them into the cold and see what happens. 



MET CALF: I would like to make just one comment. I think 

 we are all aware of the importance of the genetics of the host 

 that we are using, but I wonder if there might not be more subtle 

 relationships that we may be missing. For example, Weir' and 

 others have utilized sub- lines within a given species which vary 

 significantly with regard to blood pH, This may be of importance 

 in phagocytosis and perhaps some of the mechanisms that you 

 are measuring. I wonder if we may be overlooking these re- 

 lationships and consequently failing to assess or evaluate properly 

 some of the results obtained. 



SULKIN: My ears perked up at the comment you made, and I 

 happened to think of the experiments that we recorded a few years 

 ago on bacteriophage clearance in people and animals — rab- 

 bits, in this case. As you know, when bacteriophage has been in- 

 troduced intravenously into a rabbit it is inactivated quite promptly 

 and you can't detect phage in an animal, actually, within a couple 

 of hours. And we have the impression that perhaps properdin 

 ^\as the component that was inactivated and undertook an ex- 

 periment in which we treated these animals with zymosan, and 

 zymosan did something that depressed properdin, because phage 

 would then persist, and this has a bearing on the point that Dr. 

 Berry mentioned. 



MITCHELL: My one question is this: Dr. Berry and his group 

 and the group at Wisconsin, got to comparing notes. We have 

 experiments wherein one is performed at pressures of about 

 100 mm less atmosphere than are the ones that are performed 

 at Bryn Mawr or at Wisconsin. I wonder if this small differ- 

 ence may make them into different animals. The reason I am 

 saying this is because I knew of your own experience with al- 

 titude exposures, and I don't know whether you combined this with 

 cold. 



BERRY: I would like to say that Joe Wilson and I have been 



7 Weir, J. A. 1949. J. Infect. Dis. 84: 252-274. 



213 



