316 The Philippine Journal of Science  4oe 
leaves, with low pressures exerted, resulted in no infection. Up 
to the pressures registered with the mercury column at 10 
centimeters the results were largely negative. The few excep- 
tions to this are easily understandable from the notes from 
the field notebook, appended below the table; nevertheless, the 
results from twig 11 do not seem possible of explanation from 
the recorded data. It only seems possible that the twig was 
abnormal, or that some slight insect attack resulted shortly after 
immersion of the leaves. With the exception of this one twig 
the results are completely consistent. Even above the pressures 
of 10 centimeters there was no general infection until pressures 
TABLE 3.—Showing the results of immersing leaves of a grapefruit seedling 
tree in an infusion of Pseudomonas citri and exerting graduated de- 
grees of pressure upon such leaves. 
No, of inewhe- 
Pressure./Twig No. o Condition of leaves. tion Cankers. 
twig. period. 
cm. Days. 
0.0 1 Cente STOW. ono oon coc ckanen 10 | None. 
0.90 1 St Sl GION sewaes sercicc de os ck sce n anc ck 10 | 28 
0.0 1 St Ss ee a ee ae 10 | None. 
0.0 2 One-third grown 10 | Numerous. 
0.0 2 Sess GY ee ae ea 10 Do. 
0.0 2 10 | Full grown 10 | None. 
0.0 2 Beets Oe gar ee 10 | 2 
0.0 8 4 | Three-fourths grown¢___._-.._.__---_---- 27 | Numerous 
2.0 2 oy Pallorowh Soo ee ee 10 | 2 
2.5 a 2 {Salt grows ea 10 |} None. 
4.5 2 <4 Pell grtacce ee a 10} 2 
5.0 3 A recess (5 pope aR ICEA ae 27 | Numerous 
5.3 1 8 | Half grown 10/1 
6.5 1 4 | Two-thirds grown neue 10 | None. 
1.7 3 Os Full erown ee ca . 27 | Numerous. 
8.0 2 © teases Pe het 10 | None. 
48.2 1 .§ }| Three-fourths grown -____......-.-------- 10 Do. 
10.0 2 Chk Ree tke 10 | Numerous. 
10.1 3 5 | Full grown ars 27 Do. 
10.4 3 1| Half grown -_- a eae 27 | 8 
12.5 2 5 | Three-fourths grown .......--.----------- 10| 8 
413.0 1 6 | Full grown ai oaseubakun avon 10} 1 
414.3 3 2} Half grown _ 27 | Numerous. 
14.4 3 6 beesca ea aa 27 Do. 
15.0 2 Lg Sans Cb Sa SS, 10 Do. 
418.0 2 8 | One-third grown_-_ nae 10 Do. 
428.0 3 8 | Full grown_______ Ce as yt ar de Sa gE 27 Do. 
4 At wounds. 
x + 
» Numerous; this observation was recorded only when an accurate count of the cankers 
was impossible because of their number. . 
it -miner injuries present. 
4 Injected. 
