210 IVAN E. WALLIN 
7. Unknown bacilli and spores, apparently a pure culture made 
from the intestinal contents of a five-day-old kitten. The bacilli 
were moderately stained, no granules apparent. The spores did 
not appear to have absorbed any of the dye. 
8. Unknown cocci, culture made from a human throat swab. 
The cocci were moderately stained, no granules apparent. 
9. Unknown bacilli, culture made from a lymph node of a 
rabbit. Apparently not a pure culture. Some bacilli stained 
faintly, others quite intensely. Some large bacilli that were 
faintly stained contained intensely stained granules. 
10. Unknown bacilli and spores, culture made from a lymph 
node of a rabbit. The bacilli were moderately stained. The 
spores were decidedly tinted by the dye. 
11. Unknown bacilli and cocci, culture made from a lymph 
node of a rabbit. Bacilli and cocci were moderately stained. 
12. Unknown cocci, culture made from a lymph node of a 
rabbit. Preparation contained cocci of two sizes. Larger cocci 
were intensely stained, the smaller forms were moderately stained. 
The difference in staining was also demonstrated in the two forms 
when they were stained with Loeffler’s methylene blue. 
13. Bacillus coli, pure laboratory culture. The bacilli stained 
intensely immediately after the dye was applied, a few forms were 
only faintly stained. After the stain had acted for five and a half 
hours, the majority of the bacilli were swollen and contained a 
single large intensely stained granule. Figures 8 to 9 are 
camera lucida drawings of the preparation immediately after it 
was made and five and a half hours later. 
DISCUSSION 
The results recorded above demonstrate that the mitochondrial 
methods used are not specific for mitochondria, but that they 
also stain bacteria. The intensity of the stain varied with the 
different strains of bacteria used and apparently there was a 
variation in intensity with the different methods on the same 
strain of bacteria. Such variations apparently, also occur with 
mitochondria. The janus green vital staining method appeared 
to be the most delicate of the methods used. 
