E. J. BUTLER 21 



when they were transplanted with all the soil into larger jiots on tlie vcrandaii. 

 So long as the humidity round the plants is not kept at a higli level, infection 

 cannot be secured. Occasionally, however, the natural monsoon humidity rises 

 to a point, even within doors, when motion becomes possible and the plants can 

 be climbed. Thus on 21-8-'17, two shoots were placed with their bases immersed 

 in a few c.c. distilled water containing worms, the shoots projecting about 4 inches 

 into the air. They were left on the bench, uncovered. By the 26th they were 

 distinctly chlorotic, and on dissection were found to be full of worms in the bud 

 folds right up to the apex. The 8 A.M. relative humidity recorded at tlie Pusa 

 meteorological station averaged 87 per cent, for the five days the experiment 

 la.sted, while in the laboratory it exceeded 90 at 7 A.M. on most days, falling 

 however to 80 or lower by noon. A similar experiment on 4-9-' 17 only yielded a 

 few worms in the basal half-inch, none having reached the upper part, when 

 dis.sected 3 days later. This was a drier period than the last, the average 8 a.m. 

 humidity having fallen to 83. 



IV. l-l2-'Io, sowed paddy in a glass basin in J inch distilled water, together with 



freshly collected actively motile worms, and kept covered so that the air remained 

 saturated. 13-12-' 15, found many living worms collected on a piece of young 

 paddy leaf in the water and placed this in contact with one of the seedhngs at 

 water level. 19-12-' 15, this seedling distinctly chlorosed. Examined and fomad 

 heavily infected above the water level. 3-l-'16, many of the seedlings now well 

 infected and the worms found in the shoot above water in all the irmer layers of 

 the leaf bud. 22-1 -'16, repeated the experiment in two other basins, using seedlings 

 19 days from sowing. 27 to 30-1 -'16, infection successful in seedlings of one 

 basin, and 31-1-'16 in those of the other. Shoots chlorosed and worms found in 

 the bud layers well above water. 



V. 22-l-'16, transplanted 3 seedlings, 19 days from sowing in water, into each of 4 small 



pots. Kept standing in water covered by bell jars. 28-1 -'16, inoculated a pot 

 containing 2 seedlings (the 3rd had failed to survive transplantation) by inserting 

 pieces of the inner white shoot bud of seedlings from the last experiment, con- 

 taining worms, between a jiartly expanded leaf and the shoot. 23-2-'16, both 

 the inoculated seedlings dying, having shown symptoms of attack about a week 

 after inoculation. Only one Tylenchus could be found on dissecting the plants, 

 the others having probably left the drying plants in search of fresh food. Of the 

 9 uninoculated seedlings, 1 was attacked by fungus {Helnmithosjjoriutn Oryzce) 

 and the rest were perfectly healthy. 



VI. 2-l-'17, sowed paddy in distilled water. 29-l-'17, transplanted 2 seedlings into 



each of 2 small pots, in one of which buried (about ^ inch below surface of soil) 

 a few empty florets containing Tylenchus angustus, from plants from a plot that 

 had ripened in late November and had been left in the field. Kept standino- in 

 water, covered by bell jars. 21 -4-' 17, examined the plants. One of the seedlings 

 in the inoculated pot was apparently healthy and contained no worms ; the other 

 had brown stains on the sheaths as in ufra and there were a good manv active 

 Tylenchus aimusta^i in the inner layers of the shoot. The 2 seedlings' in the 

 uninoculated pot were healthy and had no Tylencki on them. 



VII. The plot inoculated at Pusa in August -September, 1912, as described on p. 13 of 

 the previous paper, ripened at the end of November and was a good deal damaged 

 by ufra. It was left until March 28th, 1913, when the stubble both in it and in the 

 uninoculated plot was cut and dug in to a depth not exceeding 3 inches. Lc>cal 

 seed was sown the same day in both plots. Water was nm on and kept standing 

 as usual in paddy growing. By August there was a marked difference in the two 

 plots, that previously inoculated being about 6 inches lower than in the other and 



