October 31, 1902.] 



SCIENCE. 



101 



near the center. Well-developed colonies are 

 translucent and yellowish under the micro- 

 scope by transmitted light. Colonies not 

 crowded may reach 3 mm. in diameter before 

 ceasing to increase. In bouillon a marked 

 growth is visible after eighteen hours, with- 

 out pellicle or clouding, the sedimenting white 

 growth clinging to the sides of the tube. After 

 ten or fifteen days the brown pigment makes 

 its appearance, diffusing throughout the 

 medium and the sediment takes on a dirty- 

 brownish color. Gelatine is liquefied, the 

 liquefaction in tubes at first crateriform or 

 funnelform, but may become stratiform, 

 reaching the walls of the tube and extending 

 down horizontally. Occasionally the lower 

 end of the stab liquefies the faster and pro- 

 duces a terminal sac of liquefaction. Blood 

 serum is liquefied, with production after three 

 or four days of the brown color, which be- 

 comes much darker with age than in old agar 

 cultures. On ordinary acid potato no growth 

 occurs. On neutral potato a very scanty 

 growth takes place, becoming visible about the 

 third day, not increasing after four or five 

 days and never producing color. It grows 

 abundantly in neutral milk, without coagula- 

 tion, reaction unchanged or becoming slightly 

 acid, the milk peptonizing and becoming 

 nearly clear in from one to two weeks. 



The optimum temperature is not far from 

 20°C. In the refrigerator between 3° and 

 6°C., no visible growth occurs, but the organ- 

 ism is not injured. A temperature of 31°C. 

 inhibits somewhat the growth and of 37.5°C. 

 arrests it entirely and the organism is killed 

 by an exposure to it of seventeen hours. 

 Bouillon cultures are sterilized by an exposure 

 to 42° C. for ten minutes. A culture on a 

 sealed agar slant was still alive at the end of 

 seven months. The rate of growth and 

 chromogenic property were markedly inhibited, 

 but both were restored by repeated transfers. 



In vacuo, by exhaustion with a Chapman 

 pump and absorption of oxygen by pyrogallic 

 acid and caustic potash a slight multiplication 

 occurs, apparently due to a trace of oxygen 

 at the beginning of the experiment. The 

 growth does not increase and the organism is 

 probably an obligate aerobe. It does not fer- 



ment glucose, lactose or saccharose, and does 

 not produce indol, phenol, ammonia (in 

 bouillon), invertin or diastatic ferments. It 

 reduces nitrates to nitrites and finally to 

 ammonia. Cultures in one per cent, glucose 

 bouillon acquire an acidity or increase of 

 acidity of 1.2 per cent to 1.6 per cent, in 

 fifteen days, without production of the brown 

 color; while in lactose or saccharose bouillon 

 a very slight or no development of acidity 

 occurs, and the pigment is produced much as 

 in plain bouillon. 



It is pathogenic particularly to the brook 

 trout (Salvelinus fontinalis) and has been 

 isolated from the Loch Leven (8almo trutta 

 levencnsis) in epidemic, and in a few cases 

 from the lake trout (Cristivomer namaycush). 

 It has been found only in domesticated or 

 aquarium fish and never in wild trout from 

 the natural waters. It is not pathogenic to 

 warm-blooded animals, and trout dead of the 

 disease may be eaten after cooking, without 

 harm. 



After several months and repeated transfers 

 on artificial media, it may slightly cloud 

 bouillon, and exhibit a more pronounced 

 Brownian movement to a degree suggesting 

 motility. Attempts to stain flagella have had 

 negative results, and the species is placed in 

 Bacterium and named truttce for the group 

 of fishes that apparently contains its chief 

 hosts. M. C. Maesh. 



U. S. Fish Commission. 



DISCOVEEY OF A MUSK OX SKULL (o^^BOS CAVI- 



FRONS LEIDY), in WEST VIRGINIA, NEAR 



STEUBENVILLE, OHIO. 



At the fifty-first meeting of the American 

 Association for the Advancement of Science, 

 held in Pittsburgh, June 28 to July 23, 1902, 

 Mr. Sam Huston exhibited a portion of the 

 skull of a musk ox recently found near Steu- 

 benville, Ohio, at the same time making a ver- 

 bal communication relative to the discovery 

 of the specimen. Mr. Huston has lately sent 

 to the writer for publication the following ac- 

 count of the finding of this skvill, together 

 with the accompanying sketch of a cross- 

 section of the Ohio Eiver valley at the point 

 where the skull was found : 



