366 
The third series was made December 15, from 4 to 5 p. m., including 
experiments 10 to 14; and on December 16, from 11 a. m. to 2 -p. m., 
including experiments 15 to 30. A light rain of ten or fifteen minutes' 
duration occurred on the evening of December 16, about 9.30 p. m., 
with two or three days thereafter without rain. 
The final series of experiments was made January 23, 1895, from 4 to 
6 p. m., including experiments 31 to 42; and on January 24, from 10 to 
12 a. m., including experiments 43 to 46. On January 25 a light rain 
with sleet occurred in the evening, and on the 28th there was a heavy 
fall of snow. 
Varying results on different parts of the same tree. — Later examina- 
tion of the trees treated exhibited a marked difference in the results 
of many of the washes on different parts of the trees. It was found 
that where the scales were most thickly massed on the older and lower 
parts of the trunk the wash had been most efficient, and frequently in 
these situations scarcely a living scale could be found, while on the 
extremities of the branches, where the scales were scattering, the per- 
centage of living scale in sects greatly increased. This is evidently 
due to the fact that the smooth terminals, especially those of peach, do 
not retain much of the wash, and lose it more readily under the action 
of rains; also that the scales in these situations are better nourished 
and perhaps more vigorous than where more thickly clustered. The 
dense incrustation of the scales on the bark produces also a roughness 
which holds the emulsion, and the emulsion naturally accumulates on 
the basal portion of the branches. With many of the more satisfactory 
experiments a certain patchy result was noted. In other words, on 
particular branches or sides of branches every scale would be destroyed, 
while elsewhere a considerable percentage of living scales would be 
found, sometimes confined to small areas. This would seem to indicate 
either a failure to drench the tree evenly, or else that the patchiness 
was due to the action of subsequent rains and snows. The former is not 
likely, because especial care was taken to thoroughly wet the trees, 
and careful examination Avas made after each spraying to see that 
this had been accomplished. The latter theory is probably the correct 
one, and it is supported by the fact that the experiments of December 
15 and 16 were followed by a light rain of a few minutes' duration from 
the northwest, while those of January 23 and 24 were affected by the 
irregular melting of subsequent snows, which lodged to a considerable 
extent in the trees. 
The facts noted offer an additional reason for making the treatment 
early in the fall, viz, that the wash may act over as long a period as 
possible. That treatment is best made as soon as the leaves fall has 
already been suggested by Mr. Howard, on the ground that the insects 
at this time are more susceptible than later in the fall. (Insect Life, 
vol. vn, p. 295.) A third advantage which would accrue in the East is, 
that at this season rains are much less frequent than they are in mid or 
late winter or early spring. 
