652 BACTERIA OF THE SURFACE OF THE BODY 
tat in the mouth, where the conditions as to temperature, moisture, 
and presence of organic pabulum are extremely favorable for their 
development. A minute drop of saliva spread upon a glass slide, 
dried, and stained with one of the aniline colors, will always be 
found to contain an immense number of bacteria of various forms. 
Some of these are attached to epithelial cells and some scattered about 
singly or in groups. Among those seen in a single specimen we will 
usually find cocci in tetrads, in chains, and in irregular groups, 
bacilli of various dimensions, and occasionally spirilla. According 
to Prof. Miller, of Berlin, the following species almost invariably 
occur inevery mouth: Leptothrix innominata, Bacillus buccalis max- 
imus, Leptothrix buccalis maxima, Iodococcus vaginatus, Spirillum 
sputigenum, Spirochete dentium. All of these fail to grow in ordi- 
nary culture media. Miller has made extended attempts to obtain 
cultures by varying the medium used and attempting to imitate as 
nearly as possible the natural medium in which they are found; but 
his attempts have been unsuccessful, or nearly so—“ only line cultures 
afforded a limited growth, but the colonies never developed more 
than fifteen to twenty cells, aud a transference to a second plate 
proved futile, no further growth taking place.” 
Up to the year 1885 Miller had isolated twenty-two different 
species of bacteria from the human mouth. Ten of these were cocci, 
five short bacilli, six long bacilli, and one a spirillum. Later the 
same author cultivated eight additional species. Vignal has isolated 
and described seventeen species obtained by him in pure cultures 
from the healthy human mouth; most of these are bacilli, and Miller, 
who found micrococci to be more numerous, supposes the difference 
in results to be due to the fact that many of the cocci do not grow in 
nutrient gelatin, which was the medium employed by Vignal. In 
the researches of the last-named author the following species were 
obtained most frequently, in the order given: 1. Bacterium termo. 
2. Bacilluse (Bacillus ulna ?). 3. Potatobacillus. 4. Coccusa. 5. 
Bacillusb. 6. Bacillusd. 7%. Bacillus c (Bacillusalvei ?). 8. Bacil- 
lus subtilis. 9. Staphylococcus pyogenesalbus. 10. Staphylococcus 
pyogenes aureus. 
Among the species above enumerated we find two of the most 
common pus cocci, Staphylococcus albus and aureus, but no mention 
is made of another important pathogenic micrococcus which is fre- 
quently found in the healthy human mouth, viz., the micrococcus of 
sputum septicemia, first named by the writer Micrococcus Pasteuri. 
This does not grow at ordinary temperatures, and consequently 
would not be obtained in gelatin plate cultures. Very different re- 
sults have been reported by different observers as to the frequency 
with which the pathogenic cocci are found in the buccal cavity. 
