1 82 BACTERIA IN RELATION TO PLANT DISEASES. 



Harding inoculated Bact. campestre into animals with negative results. 



Harrison inoculated Bacillus solanisaprns into guinea-pigs and rabbits without positive 

 results (see Vol. Ill, Basal Stem-rot of Potato). 



The following experiments with fishes in water containing bacteria of plant diseases 

 were undertaken for me in 1905 by M. C. Marsh, bacteriologist of the Bureau of Fisheries, 

 in Washington. I prepared the cultures myself. The summary is his: 



Bacillus aroidcac. About 25 liters Potomac tap water in glass aquarium jar, with constant flow 

 of air in small bubbles delivering at the bottom. Two sunfish, 1 small goldfish, and 1 mummichog 

 were used with 14 cc. of a well-clouded 2-day bouillon culture of B. aroideae introduced on first day, 

 February 17, 1905; March 5, 15 cc. of a 5-day culture added. March 13, after 26 days, all fishes 

 alive and in good condition. 



March 5, injected largest of the above sunfish behind eye with about 0.5 cc. of a 5-day well- 

 clouded bouillon culture of B. aroideae; producing great exophthalmia. Sunfish remained in jar 

 containing B. aroideae mixed with water. March 13, fish aiive, eye normal; time 8 days. 



Bacteria of carnation leaf spot, February 19, about 25 liters Potomac tap water in glass aquarium, 

 aeration as above. One small black bass (5 inches), 2 sunfish, 1 mummichog. February 20, added 

 two 20-day bouillon cultures of carnation bacteria, one 5-day bouillon culture, and one 20-day agar 

 slant culture; February 28, added three 9-day bouillon cultures. 



March 13, after 21 days, all fish in good condition. 



Temperature of water 14. 5 to 22 C. No change of water during experiments. Fishes fed 

 very sparingly. 



In transmitting the above report Mr. Marsh made the following comment : 



I send you herewith a statement of the effect of the plant bacteria on fishes, from which it 

 appears that the effect is nil. I did not make a direct inoculation with the carnation rot, on account 

 of the result with the presumably more dangerous calla rot. It is not likely that these organisms 

 would harm any fishes, though I was unable to try trout. The eye inoculation should have taken if 

 there was any pathogenicity about the calla rot for fishes. 



Inoculations of Bact. tumefaciens into Fish and Frogs. 



In the spring of 1908, the writer made fourteen sets of inoculation experiments on fish 

 and frogs with pure cultures of Bact. tumefaciens derived from tumors on the hothouse 

 daisy (Chrysanthemum) to determine whether this organism would induce similar abnor- 

 mal growths in cold-blooded animals, experiments on warm-blooded animals being con- 

 sidered unnecessary because of the low maximum temperature of the organism (about 

 36. 5 C). 



These inoculations were carried on in Washington in houses belonging to the Bureau 

 of Fisheries with trout and roach kindly placed at my disposal from the stock tanks and with 

 frogs bought from a Washington dealer. With exception of those used in Experiment IX, 

 the trout were 8 to 10 inches long and were ordinary brook trout (Salvelinus fontanalis) . 

 The roach (Abramis chrysoleucus) were about 6 inches long. There were no checks on the 

 roaches or frogs. The checks on the trout consisted of a school of about 100 fish of the same 

 age and condition, and of which those I took had previously formed a part. These were in 

 one of the ordinary exhibition tanks of the Bureau along with some rainbow trout. They 

 were not checks in the strictest sense of the word because they were not wounded in any 

 way. 



Inoculations of March 20, 1908. These were made from four agar streak cultures 

 48 hours old. None of them were hypodermic injections. 



I. Two trout. Each two needle-oricks in the eye-socket. 



II. Two trout. Each three needle-pricks in the region of the anus. 



III. Two trout. Each three or four needle-pricks in the fleshy fin (adipose). 



