62 



IMMUNITY IN HEALTH 



bacteria and of soot particles in the lymph nodules of 

 the wall of the alimentary canal. He successfully 

 demonstrated bacteria in the appendix, tonsils and 

 Peyer's patches of the rablDit, and the Peyer's patches 

 and tonsils of the dog, and the Peyer's patches of the 

 guinea-pig. Dr. Ruffer in his paper referred to similar 

 observations five years earlier by two independent 



Fig. 2T. 



From a photograph of micrococci in the lymphoid tissue of a 

 healthy rabbit's tonsil. (Eosin-Gram stain; 1/12 in. objective.) 



observers, Ribbert and Bizozzero, but I have been un- 

 able to trace the references he gives. In spite of the 

 high standard of Dr. Ruffer 's histological demonstra- 

 tions the piece of knowledge appears to have fallen 

 into the background. 



In my own experiments the rabbits were killed very 

 quickly by fracture of the cervical spine, chloroform, 



