Cultivation and Management of Hops. 
353 
matters, and, being put into the mixen, is ready for carting 
after once or twice turning. This is a great improvement upon 
the old system of putting the bundles of bines, 3 feet long by 2 
feet wide, green into the yards, or the alternative of putting them 
in stacks for a year, to become brittle and be more easily trodden 
to pieces by bullocks. Covered yards or covered mixen places 
are not thought necessary ; but the latter have either brick and 
cement dams where the ground falls, or the ends and sides of 
the mixens are carefully plastered with mud to prevent the 
escape of the liquid manure. 
Blights. 
Aphides, or Plant-lice. — Various and wild have been the 
theories and speculations as to the origin of aphides, the cause 
of blight in hops. It has been gravely maintained, even by 
close observers, that the eggs of these aphides are wafted 
by the east wind in that peculiar blue mist or haze which 
so often accompanies it. Some scientific men asserted that 
the atmosphere is laden with the eggs of insects ; but as the 
specific gravity of the eggs of every known species of insect is 
greater than air, these were manifest delusions. Moreover, the 
fertilized eggs of aphides, according to Latreille, are covered with 
a sticky substance, so that they remain through the winter where 
they are deposited in the autumn, and those that escape the action 
of wet, frost, and other accidents, are hatched in the spring as 
the perfect winged insects. 
It is true that blight most often occurs after cold east winds, 
dark gloomy weather, and in seasons of sudden variations of 
temperature. These variations affect and alter the juices or sap 
of the plant, causing an excess of saccharine matter, at the same 
time affording suitable and attractive food for the aphides, which 
are always present, ready to seize upon the opportunity, their 
increase and power of blighting depending solely upon the quality 
and quantity of the food thus provided for them. With regard 
to the " honey dew," the viscid substance which is spread on 
the upper surface of the leaves after the aphides have been at 
work for some time, the effect has been mistaken for the cause. It 
has been thought that this was a morbid exhalation of the leaves, 
and that it attracted the aphides by its sweetness. That generally 
accurate observer White, of Selborne, was deceived as to this, 
failing altogether to perceive that it is caused by the insects them- 
selves ;* that it really is the excretion of the countless generations 
* " The reason of honey-dew seems to be that in hot days the effluvia of 
flo-wers are drawn up by a brisk evnporation, and then in the night fall down 
with the dews, with which they are entangled." — White's ' Natural History of 
Selborne,' p. 304, 
