EXPERIMENTS WITH THE DAISY ORGANISM. 33 



The tumors have a rough, corky surface quite distinct from any wound reaction due 

 to the needle punctures. 



Plant H, Madame Peyre: Shoot has grown 3 inches since it was punctured. There 

 are 3 little tumors on the midrib of a leaf, and 5 below this on the stem. 



Plant I, Single \\Tiite: This is one of the tall single-stem plants. It has grown about 

 10 inches beyond the point of inoculation and is budding ready to bloom. The shoot 

 bears 9 distinct tumors, the largest of which are about 4 millimeters in diameter and 

 about 3 millimeters high. Some are on the stem; some on the base of a petiole. 

 Three needle punctures have failed to give any distinct growths. 



Plant K, Single White: This is a tall plant, consisting of a single shoot. It has 

 grown beyond the point of inoculation a distance of about 9 inches. The tumors are 

 on the stem. They have mostly fused into a rough, brownish mass, but there are 2 or 3 

 separate ones. Their height above the surface of the green stem is perhaps 2 to 3 

 millimeters. 



The last two plants and the one confined to a single stem (Plant F) 

 have made much the greatest growth beyond the point of inoculation, 

 and corresponding to this the tumors also are larger than on any of 

 the others. This fact, taken in connection with the small, imperfect 

 development of tumors on Plant E, which has made the least terminal 

 growth, is very instructive and points without doubt to the conclusion 

 that the amount of tumor growth is dependent upon the rapidity of 

 growth of the shoot itself, i. e., the condition of nourishment of the 

 part — a slow-growing shoot would have slow-growing tumors, but a 

 rapid-growang shoot would develop correspondingly large ones. 



These plants have now been inoculated nearly two and one-half 

 months and have developed very good tumors for the amount of 

 time, judging from Clayton O. Smith's statements respecting the slow 

 growth of natural tumors on the oleander. 



The Paris daisies inoculated at the same time for controls developed 

 good-sized tumors promptly. 



The final photographs (reproduced in PL III, figs. B, D) were made 

 October 28, 1908. 



DAISY ON OLIVE. 



Inoculations of February 14, 1907 (Brown). 



Two olive trees about 2 feet tall were inoculated on all the young 

 shoots and a few old stems, with agar streak cultures 7 days old, the 

 third subculture from the poured-plate colonies. 



Result. — April 4, 1907: No knots. 



Inoculations of March 11, 1907 (Smith and Townsend). 



A young growing shoot of olive was inoculated with a virulent agar 

 culture of the daisy organism (used also on this date for successful 

 inoculations of the peach, p. 38). 



Result. — Negative. 



78026°— Bull. 213—11 3 



