25 



enchyma in these particular places, or which have so destroyed the tissues as to 

 allow the juices to flow out. The greater part of the three inoculated leaves and 

 all of the other two leaves are sound. The leaves are now about 30 cm. long. The 

 opinion of March 1 as to the greater resistance of this variety is certainly confirmed 

 by the observations made to-day. 



June 16. The basal 15 era. of two of the inoculated leaves is sound. On the third 

 it is sound, except for a narrow, interrupted, water-soaked stripe which extends to 

 within 5 cm. of the bulb. The bulb was carefully sectioned at various levels from 

 the base of the plateau to the top of the scales, but there was no trace of yellow 

 bundles or any other symptom of disease. Of course it does not follow that some 

 of these bacteria had not gained entrance to the underground parts or that six 

 months later this bulb would not have been diseased. Indeed, E believe it would 

 have been. 



Noteii on plant No. 4C.— Inoculated in apical part of three leaves on Februry 7. 



February 14. No symptoms. The plant has five leaves. ir..5 cm. long. 



March 1. Long, narrow, water-soaked lines have appeared in the injected part 

 of two of the inoculated leaves. As yet there is no yellowing. The third leaf 

 shows no symptoms. 



March 30. There are now distinct symptoms on each of the inoculated leaves. 

 The stripe on the first leaf is .5 cm. long and 3 to 5 mm. wide. It is brown in the 

 upper (widest) part, where the bulk of the injected fluid must have lodged. The 

 tip of the second leaf is dry and brown (3 cm. ) , and in tlie middle of the leaf from 

 this point down for a distance of 8 cm. the symptoms continue in the form of nar- 

 row, interrupted, water-soaked stripes. On the third leaf the yellow stripe is 

 5 mm. broad in its upper part and 1 to 2 mm. wide in the middle and lower part. 

 Farther down the stripe is composed of narrow, interrupted, water-soaked lines 

 on a green background. No part of the stripe is brown. The rest of the plant is 

 normal. Here, as in No. 45, the symptoms on one leaf did not develop until after 

 twenty-one days, and from the present appearance probably not until more than 

 thirty days had passed. This is very remarkable, considering the number of 

 germs used, and can be explained only on the supposition that most of them have 

 been destroyed in the plant or, if not killed outright, have been able to overcome 

 retarding influences only very slowly. 



June 16. The basal 5 to 15 cm. of each leaf is sound externally; the rest is dead 

 and dry. The bulb is sound externally. On cutting open, one scale only was 

 visibly afifected. This scale bore one of the inoculated leaves, and the visible 

 symptoms were restricted to the upper third of the bulb and to one bundle. The 

 p'ateau and all the other scales were free from symptoms, but probably a careful 

 microscopic examination would have shown the beginning of disease in other 

 bundles of this scale. 



SERIES 8 (HYACINTHS). 



The eighth series of inoculations was made February 11 in the same 

 manner as the preceding. For this experiment two pbxnts of the variety 

 known as Gertrude were selected, and two plants of the same variety, 

 in the same pot, were hekl for comparison. This variety is a deep- 

 rose, single-flowered, vigorous-growing sort. The plants were in full 

 bloom. One had eight leaves, the other nine. Three leaves on each 

 plant were inoculated near the apex from the well-clouded beef-broth 

 culture (No. 0, Feb. 5), 0.3 cc. being injected into each leaf. These 

 leaves were 10 to 12 cm. long. The needle was inserted about 2.5 cm. 

 from the apex of the leaf, and the narrow, su (fused (water-soaked) 

 stripe which appeared immediately after the injection of the fluid often 

 extended nearly to the base of the leaf. 



