192 
The N.Z. Journal of Science and Technology. [Nov. 
3. The General Progress of the Disease as shown by the 
Marked Plants. 
Owing to a very considerable number of the marked plants at Ashlea 
having been cut down soon after the marking, to cattle displacing the 
labels, to the difficulty in finding marked plants where the flax has increased 
in density, and to the exceedingly wet state of Miranui, except at the last 
examination the number of plants examined on each occasion was consider¬ 
ably less than I had anticipated. All the same, the number examined is 
sufficient to give reliable indication of the procession of events. 
The table below, read in conjunction with the remarks directly following 
it, gives a clear idea of what happened. The Miranui and Ashlea plants 
are taken together. The dead plants are counted in with the diseased. 
Plants recovering and plants which recovered are taken together for the 
sake of emphasizing recovery, recovering plants being in the majority 
of cases to all intents and purposes healthy. So, too, many of the 
diseased plants have greatly improved in part, and many, though classed 
as still diseased, are rapidly making excellent flax. In order to make 
the comparison between the four examinations of the marked plants 
stand out clearly, percentages are given in three of the columns rather 
than numbers. 
Table showing Results of the Four Examinations. 
No. of the 
Examination. 
Date of the Examination. 
Number of Plants 
examined. 
Number of 
Originally Healthy 
Plants 
examined. 
Percentage of 
Originally Healthy 
Plants which 
remained healthy. 
Number of Plants 
examined 
originally diseased. 
Percentage of 
Originally Diseased 
Plants recovered 
or recovering. 
Percentage of 
Originally Diseased 
Plants remaining 
diseased and not 
recovering. 
1 
2nd-5th July, 1918 . . 
301 
121 
Per Cent. 
83 
180 
Per Cent. 
72 
Per Cent. 
28 
2 
25th-27th Sept., 1918 
417 
200 
78 
217 
45 
54 
3 
21st, 22nd Dec., 1918 
357 
175 
57 
182 
40 
60 
4 
6th-8th May, 1919 .. 
338 
. 
161 
54 
177 
77 
23 
The figures in this table reflect with accuracy the procession of events 
as shown by the general changes in the aspect of the flax areas themselves 
brought forth by increase or decrease of yellow-leaf. Thus examination 
No. 1 shows the autumn and winter recovery of 1918, while examinations 
Nos. 2 and 3 reflect plainly the gradually increasing deterioration of the 
flax in the following spring and early summer, and examination No. 4 
emphasizes the remarkable recovery during the autumn of 1919. That 
this recovery must have been in progress for at least two months prior to 
the date of examination No. 4 was revealed by the appearance of the 
numerous dying leaves, and by the fact that plants diseased since 
December had recovered perfectly ; the recovery must, indeed, have been 
taking place at a date equivalent to that of the original marking, which 
I do not think was a special period of recovery. It is this early recovery 
of 1919 which can lend high hope that the disease has passed its worst 
phase. 
4. Detailed Results of the Final Examination of the 
Marked Plants. 
The foregoing table deals somewhat roughly with the history of the 
marked plants ; it does not tell a great deal more than does the changing 
