ON THE NATURE OF MITOCHONDRIA 219 
3. Staphylococcus pyogenes aureus. Cocci swollen and par- 
tially destroyed, also stained. 
4, Bacillus megatherium and spores. Bacilli could not be 
demonstrated by staining. Spores unstained, some swollen. 
4. Bacillus megatherium and spores. Bacilli and spores 
preserved, but unstained. 
5. Unknown cocci. Few swollen and stained cocci. Clumps 
of stained granular debris. 
c. After 2.5 per cent potassium bichromate. 1. Human tubercle 
bacilli. Bacilli intact could not be demonstrated by staining. 
Granular remains minute particles and intensely stained. 
2. Bovine tubercle bacilli. Few faintly stained bacilli intact. 
3. Staphylococcus pyogenes aureus. Cocci could not be dem- 
onstrated by staining. Granular remains. 
4, Bacillus megatherium and spores. Few swollen and un- 
stained bacilli. Outline of spores very faint. 
5. Unknown cocci. Cocci very faintly stained and swollen. 
F., Action of osmic acid on bacteria 
Various strains of bacteria were subjected to the action of 1 
per cent and 2 per cent osmic acid for a period of four hours. 
a. After 1 per cent osmic acid. 1. Human tubercle bacilli. 
Bacilli well preserved, stain purple. 
2. Bovine tubercle bacilli. Bacilli well preserved, stain deep 
red. 
3. Staphylococcus pyogenes aureus. Cocci preserved, but 
unstained. 
4, Bacillus megatherium and spores. Bacilli and spores pre- 
served, but unstained. 
5. Unknown cocci. Could not be seen on the slide. 
b. After 2 per cent osmic acid. 1. Human tubercle bacilli. 
Poorer preservation than with 1 per cent osmic, faintly stained. 
2. Bovine tubercle bacilli. Well preserved and intensely 
stained. 
3. Staphylococcus pyogenes aureus. Cocci could not be seen 
on the slide. | 
