416 
INSECTS WHICH DISTIL WATEE. 
Chap. XXI. 
cluster round a spot on one of tlie smaller branches, and there 
keep up a constant distillation of a clear fluid, which, dropping to 
the ground, forms a httle puddle below. If a yessel is placed 
under them in the evening, it contains three or four pints of fluid 
in the morning. The natives say that, if a drop falls into the eyes, 
it causes inflammation of these organs. To the question whence 
is this fluid derived, the people reply that the insects suck it out 
of the tree, and our own natoalists give the same answer. I have 
never seen an orifice, and it is scarcely possible that the tree can 
yield so much. A similar but much smaller homopterous iusect, 
of the family Cereopidce, is known in England as the frog-hopper 
{^Aplirophora spumarid), when full gTOwn and furnished with 
Avings; but wlnle still in the pupa state it is called “ cuclcoo~spit,'' 
from the mass of froth m which it envelops itself. The circulation 
of sap in plants in our chmate, especially of the graminacese, is 
not quick enough to yield much moisture. The African species 
is five or sis times the size of the Enghsh. In the case of branches 
of the fig-tree, the point the insects congregate on is soon marked 
by a number of mcipient roots, such as are thrown out when a 
cutting is inserted in the gTound, for the purpose of starting 
another tree. I beheve that both the English and African in¬ 
sects belong to the same family, and differ only in size, and that 
the cliief part of the moisture is derived from the atmosphere. 
I leave it for natmralists to explain how these httle creatures 
distil both by night and day as much water as they please, and 
are more independent than her Majesty’s steam-sliips, with their 
apparatus for condensing steam, for, without coal, their abun¬ 
dant supphes of sea-water are of no avail. I tried the following 
experiment:—Emding a colony of these insects busily distilling 
on a branch of the Ricinus communis, or castor-oil plant, I denuded 
about 20 inches of the bark on the tree side of the insects, and 
scraped away the ioner bark, so as to destroy all the ascending 
vessels. I also cut a hole in the side of the branch, reaching to 
the middle, and then cut out the pith and internal vessels. The 
distillation Avas then going on at the rate of one drop each 67 
seconds, or about 2 ounces 5^ drams in 24 hours. Next morning 
the distillation, so far from bemg affected by the attempt to stop 
the supphes, supposing they had come up through the branch 
from the tree, was increased to a drop every 5 seconds, or 12 di’ops 
