46 CROWN-GALL OF PLANTS. 



Result. — April 29: Some of the inoculated plants bear galls, and 

 one was photographed. 



May 9, 1907: Galls half an inch in diameter were found on all of 

 the inoculated beets; the checks had no galls. 



May 29, 1907: The gaUs had increased in size so they were now 

 2 to 3 inches across. 



Inoculations op November 15, 1907 (Smith). 



Twenty-four sugar beets (Nos. 500-519 and 523-526) were inocu- 

 lated with the daisy organism from slant agar cultures of November 

 11, 1907. The portion of the beet projecting above ground was 

 washed carefully with a clean cotton plug wet with filtered water, 

 after which a large amount of milky fluid from the slant agar cultures 

 (into wliich about one-half c. c. filtered sterile river water had been 

 poured) was put on the cleaned surface with a sterile platinum loop. 

 Ten needle pricks, about one-fourth inch deep, were made through 

 this (close together), and more of the milky fluid was added. Three 

 daisy plants were inoculated as checks on the virulence of the cul- 

 tures, one from each tube. The daisies were Nos. 520 to 522. The 

 sugar beets were from seeds planted in July, and were growing in 

 pots in the greenhouse. They had made a very fair growth and 

 were in good condition. They had good foUage, and the portions 

 inoculated were soft and not woody. The daisies were vigorous 

 young plants about 10 inches high, \vith very tender stems, and 

 were growing rapidly. They were grown from cuttings and were 

 in excellent condition for inoculation. 



Result. — December 4, 1907: Some of the sugar beets inoculated 

 November 15 were examined carefully and tumors as large as small 

 peas were found on each one. A number of the sugar beets show as 

 many tumors as there were needle pricks, i. e., 5 or 6. Some days 

 previous very young knots were cut out of these plants, to fix for 

 chromosome sections. The knots were at that time 10 days old and 

 about one-tenth part as large as an ordinary pea, or perhaps even 

 smaller than that. The daisy plants inoculated as checks showed 

 tumors. 



January 29, 1908: All of the sugar beets inoculated on November 

 15 produced well-developed tumors, except Nos. 509 and 524, i. e., 

 92 per cent. The tumors on 3 of the beets were rotting. 



Inoculations of November 18, 1907 (Smith). 



Tliirty-six sugar beets (Nos. 527 to 562) were inoculated with slant 

 agar cultures of November 15, 1907 (from slant agar cultures of 

 November 11, 1907, used for the preceding inoculation). The beets 

 were from the same lot as those inoculated November 15, and were 



213 



