270 INSECTS WHICH DISTIL WATER. 



curious insect, which inhabits trees of the fig family, 

 Ficus,) upward of twenty species of which are found 

 here. Seven or eight of them cluster round a spot on one 

 of the smaller branches, and there keep up a constant dis- 

 tillation of a clear fluid, which, dropping to the ground, 

 forms a little puddle below. If a vessel 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 natu- 

 ralists 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 insect, of the 

 family Cercopidce, is known in England as the frog-hopper, 

 (Aphrophora spumaria,) when full grown and furnished 

 with wings, but while still in the pupa state it is called 

 " Cuckoo-spit," from the mass of froth in which it envelops 

 itself. The circulation of sap in plants in our climate, 

 especially of the graminaceas, is not quick enough to yield 

 much moisture. The African species is five or six times 

 the size of the English. In the case of branches of the 

 fig-tree, the point the insects congregate on is soon marked 

 by a number of incipient roots, such as are thrown out 

 when a cutting is inserted in the ground for the purpose 

 of starting another tree. I believe that both the English 

 and African insects belong to the same family, and differ 

 only in size, and that the chief part of the moisture is 

 derived from the atmosphere. I leave it for naturalists to 

 explain how these little creatures distil both by night and 

 day as much water as they please, and are more indepen- 

 dent than her majesty's steamships with their apparatus 

 for condensing steam; for, without coal, their abundant 

 supplies of sea-water are of no avail. I tried the following 

 experiment. Finding a colony of these insects busily dis- 

 tilling on a branch of the Ricinus communis, or castor-oil 

 plant, I denuded about twenty inches of the bark on the treo« 



