206 IVAN E. WALLIN 
tures. Their nature remains as much a puzzle to-day as when 
they were first discovered. It is with a desire to point out 
certain similarities between mitochondria and bacteria besides 
the similarity of form as well as seek a specific differentiation be- 
tween the two structures that these studies have been undertaken, 
MATERIAL AND METHODS 
The materials used in this investigation have included a large 
number of strains of bacteria, some from known pure cultures and 
others from various mixed infections. The mixed specimens were 
obtained from sputum from hospital patients, pus centrifuged 
from urine, pus from a carbuncle, cultures made from the in- 
testinal contents of rabbits and kittens, cultures made from lymph 
nodes, and from various other sources. 
The staining methods employed were: Bensley’s acid fuchsin 
methyl green method, Schridde’s modification of Altmann’s 
method, Benda’s crystal violet method, the copper hematoxylin 
method and the vital janus green method. 
In the second part of this study a number of strains of bacteria 
were subjected to the action of alcohol, ether, chloroform, acetic 
acid, formaldehyde, potassium bichromate, osmic acid, and heat. 
The object of these experiments was not to determine the exact 
nature of the response of the organisms to these chemicals and 
heat, but to determine the effect on the staining reaction of the 
bacteria after such treatment. In every case controls were 
stained with the same stain used on the experimental prepara- 
tions. 
The janus green used in the vital staming was one of two lots 
that were kindly donated to the author by Professors Bensley 
and KE, V. Cowdry. This opportunity is taken to express ap- 
preciation for this helpful courtesy. Viable cultures of human 
and bovine tubercle bacilli were supplied by Dr. Harry Gauss, 
of the National Jewish Tuberculosis Sanitarium in Denver. 
I am especially indebted to my colleague Dr. Severance Bur- 
rage, of the Department of Pathology, for valuable assistance 
and suggestions in this work and also for generous use of bac- 
terial cultures in his laboratory. 
