EXPERIMENTS WITH THE BEET ORGANISM. 81 



BEET ON BEET. 



Inoculations of June 27, 1910 (Brown). 



Ten half-grown plants were inoculated on the upper ])art of the 

 root by needle pricks from a young agar culture. 



Result. — July 18, 1910: All negative. Weather hot and beets 

 making a very slow growth. 



Remarks. — The foregoing 3 experiments were made in all proba- 

 bility with the wrong organism, as shown by subsequent tests on 

 culture media. The organism used had a slightly pinkish growth on 

 agar. (See Cultural character's, p. 108.) 



ADDITIONAL EXPERIMENTS WITH SUGAR BEETS. 



Isolation of Organisms. 



In November, 1910 — i. e., since the foregoing paragraphs were 

 written — -additional galled sugar beets were obtained (1) from Colo- 

 rado, (2) from Kansas, (3) from Michigan, (4) from Arlington Experi- 

 mental Farm in Virginia, and (5) from the State of Washington. 



The material from Colorado and Kansas was not satisfactory for 

 reasons stated on page 194. From the Michigan material what was 

 supposed to be the gall organism was obtained twice (two sets of 

 plates from one gall). From the Washington material a gall-like 

 organism was obtained once. From the Arlington material it was 

 obtained 5 times (4 different beets). Two of the above tests (Arling- 

 ton) were quantitative tests. The first one was lost so far as quanti- 

 tative results are concerned, either because the sand used in grinding 

 was not sterile or because the surface of the gall v/as simply scraped 

 and then washed repeatedly in sterile waters without subjecting the 

 surface to heat or germicid:il solutions. The second test, made with 

 greater care as to sand and surface sterilization, yielded the results 

 hereafter detailed; but before these are given it will be well to put 

 before the reader the technique employed. 



On November 15, 1910, a sound, medium-sized sugar beet was 

 selected. It bears one tumor free from decay or cracks. It is 

 rounded oblong, attached by a rather broad base, and free from sur- 

 face irregularities, being covered by a thin secondary cork layer 

 (wound cork). The beet was washed clean in tap water, plunged 

 into alcohol until free from air bubbles, then into 1 : 1,000 mercuric 

 chloride water for 20 miniites. During this period the tumor was 

 scraped gently witli a knife to remove all the cork without injury to 

 the deeper tissues. With the point of the knife a few tin}'" black 

 specks extending into the white surface of the gall a very little deeper 

 78026°— Bull. 21:^—11 6 



