392 PYOGENIC BACTERIA. 
other and separated by a cleft, and some of these correspond in their 
morphology, in every detail, with the gonococcus.” 
Stains quickly with the basic aniline colors, especially with 
methyl violet, gentian violet, and fuchsin; not so quickly with 
methylene blue, which is, however, one of the most satisfactory 
staining agents for demonstrating its presence in pus. Beautiful 
double-stained preparations may be made from gonorrheal pus, 
spread upon a cover glass and “‘ fixed,” secundum artem, by the use 
of methylene blue and eosin. Does not stain by Gram’s method— 
2.€., the cocci are decolorized, after having been stained with an ani- 
line color, by being immersed in the iodine solution employed in 
Gram’s method of staining. But this character cannot be depended 
upon alone for establishing the diagnosis, for Bumm has shown that 
Fia. 86.—“* Gonococcus ” in gonorrheeal pus. From a photomicrograph by Frinkel and Pfeiffer 
x 1,000. 
other diplococci are occasionally found in gonorrhceal pus which do 
not stain by this method. Itserves to distinguish them, however, from 
the common pus cocci heretofore described—Staphylococcus aureus, 
Staphylococcus albus, Staphylococcus citreus—which retain their 
color when treated in the same way. A more trustworthy diagnostic 
character is that these biscuit-shaped diplococci are found within the 
pus cells, sometimes one or two pairs only, but more frequently in 
considerable numbers, and occasionally in such numbers as to com- 
pletely fill the cell. No similar picture is presented by pus from any 
other source, with the exception of that from a form of “ puerperal 
cystitis” which Bumm has described. But in this the diplococci 
contained in the pus cells were to be distinguished by the fact that 
they retained their color when treated by Gram’s method. Owing 
