BACTERIUM TUBERCULOSIS 453 



a cubic centimeter of a carefully prepared suspension in 

 bouillon of, let us say, Holler's grass bacillus II, be injected 

 into the circulation of a rabbit, and the animal be killed 

 after twelve to fourteen days, the kidneys will be found 

 marked by gray or yellowish points that range in size from 

 that of a pin-point to that of a pin-head. They are some- 

 times very few in number, but in other cases both kidneys 

 may be thickly studded with them. Often they are not 

 elevated above the cortex of the organ, but in as many cases 

 they are sharply defined, yellow in color, and stand up 

 prominently from the cortical surface, being at the same 

 time so adherent to the capsule that the removal of the 

 latter tears them out bodily from the substance of the organ. 

 In the very early stages of development these nodules are 

 often difficult to distinguish from young tubercles, the reac- 

 tion of the tissues being, as in the case of tubercles, charac- 

 terized by proliferation of the fixed cells with little evidence 

 of leukocytic invasion; later on, true giant-cell formation 

 is recorded by some observers. We have not seen this. 

 Clumps of endothelial nuclei or of lymphoid cells that 

 remotely suggest the arrangement seen in giant cells are 

 often encountered, but we have not regarded them as true 

 giant cells. When fully developed, the nodule may present 

 a mixed condition of caseation and suppuration. The 

 conditions, as a whole, when advanced suggest a low grade 

 of inflammatory reaction. Occasionally nodules are en- 

 countered, especially in the kidney, that cannot be dis- 

 tinguished from tubercles. The bacilli are always to be 

 found within the nodules; most frequently as single rods or 

 clumps of rods, occasionally as rosette-like mycelia very 

 suggestive of the characteristic growth of the actinomyces 



