EXPERIMENTS WITH THE DAISY ORGANISM. 37 



Inoculations of April 4, 1910 (Brown). 



Five shoots of a red-flowered plant and 7 shoots of a coarser growing 

 white-flowered sort were inoculated by needle pricks, using one of the 

 actively pathogenic recent isolations from daisy. 



Result. — June 24, 1910: All negative. 



DAISY ON CLOVERS AND ALFALFA. 



Inoculations of March 12, 1908 (Brown). 



The roots of 2 white clovers (Trifolium mpens), 2 red clovers (T. 

 pratense), and 2 alfalfa plants (Medicago sativa) were inoculated by 

 needle pricks with agar streak cultures 3 days old. Two checks 

 were held on the clovers. The inoculated roots were marked by 

 strings tied around each one below the point of inoculation. 



Result. — March 27, 1908: Galls had formed at the inoculated 

 points, but could not be distinguished at this date from the regular 

 tubercles on clover. 



May 14, 1908: The plants were dug up and the marked roots 

 examined. Small galls one-fourth to half an inch across and quite 

 distinct in appearance from the nitrogen tubercles were now present 

 on the inoculated roots where the needle pricks were made. One 

 gall had many projecting hairlike roots, making it resemble the apple 

 or peach gall of the hairy-root type.** 



Inoculations op May 26, 1908 (Smith). 



Five plants of scarlet clover ( Trifolium incarnatum) were inoculated 

 on the fleshy roots with the daisy organism from agar streaks 4 days 

 old. These plants were dwarfed in 3-inch pots, but stood on earth 

 and had rooted into it beneath the pots. The crowns were uncovered, 

 then inoculated, and repotted in 6-inch pots. The plants had each a 

 half dozen or more shoots, and were about 8 or 10 inches high. Those 

 which had not yet blossomed were selected for this experiment. A 

 daisy plant inoculated from the same culture was held for control. 



Result. — Negative. Plants growing slowly and probably too old. 

 Their roots were also injured in repotting. 



According to j\lr. Karl F. Kellerman (verbal communication), a gall 

 of a similar character to that obtained b}^ us occurs naturally on 

 clover in some parts of the United States, and had been a source of 

 confusion to him. 



a Viala has figured a galled vine shoot (brousslns) bearing also aerial roots. 

 213 



