412 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
The organism does not form spores, and a capsule has not been demonstrated. 
Old cultures show no marked change in the form of the organism. 
Staining reactions . — It stains readily by the ordinary aniline dyes in aqueous 
solution. Thionin and methylene blue give excellent results. Unstained areas 
are occasional, but not particularly characteristic. The reaction with Gram’s stain 
is not of much value. It stains faintly by this method, but films stained for thirty 
seconds in aniline-gentian-violet will retain some stain after considerable washing in 
alcohol, whether the iodine solution is applied or not; so that the ordinary routine 
of Gram’s method is of little value as indicating the applicability of Gram’s stain to 
this organism as a differential staining property. If, however, the gentian violet is 
applied instantaneously and then treated with the iodine solution, it is seen that the 
organisms retain the stain after the washing in alcohol better than control films 
which have not been treated with the iodine. The iodine has at least some fixing- 
power with the gentian violet, and the organism therefore stains by Gram’s method. 
Cultural characters. — Growth occurs in the ordinary nutrient media, luxuriantly 
at a titre neutral or +0.5 to phenolphthalein; it will not grow, or but very slightly, 
at +1.5; at —0.5 growth is inhibited, and at —1.0 to —1.5 scarcely occurs. The fol- 
lowing descriptions of cultures refer to media whose titre is +0.5 to phenolphthalein 
unless otherwise stated. The media employed were prepared from ingredients chem- 
ically pure, or as near so as the market affords. Unless otherwise stated herein the 
procedures® recommended to the American Public Health Association by its com- 
mittee of bacteriologists were followed throughout, save that Liebig’s extract of 
beef was employed instead of fresh meat. 
Bouillon: A marked growth is visible after eighteen hours, without pellicle or 
clouding, but with the sedimenting white growth clinging to the sides of the tube. 
After about five days a delicate interrupted pellicle may form, and numerous Hoceuhe 
are distributed throughout the medium, both of which sink readily and upon the 
slightest agitation. After ten or fifteen days a characteristic brown color makes its 
appearance, diffusing throughout the medium, and the sediment takes on a dirty 
brownish color. The color deepens with age to a dark brown. 
Agar-agar: On +1.5 slants it scarcely grows. After twelve days a slight 
multiplication is indicated by a pale filmy streak, visible best when held in the light 
against a dark background, and which has not increased after several weeks. The 
condensation water contains a slight sediment. No color is produced. Growths on 
agar of this titre are not sufficient to characterize the species. On +0.5 agar 
moderately abundant growth occurs of a grayish-white color, which with age becomes 
grayish brown. On usually the third day a production of a soluble pigment 
becomes evident, which diffuses in the medium and does not reside in the growth 
itself. It is a reddish-brown shade and deepens gradually until after two or three 
weeks it becomes a very dark brown, and the growth itself takes on a tinge of brown. 
In an agar-stab culture a growth of the usual features, with nothing particularly 
characteristic, occurs throughout the line of puncture, and an umbilicate surface 
growth takes place which is nearly circular and reaches a diameter of about 5 mm. 
in five days. Very faint color is visible by the third day, diffusing slowly downward 
a Procedures recommended for the Study of Bacteria, etc., Jour. Amer. Pub. Health Assn., vol. 23, 1898, 56. 
