109 

This is the case with the leaves of the Lime (Titia), for although some authors have disputed the fact a most 
capable judge, Dr. Maxwell Masters, informs mo that, having heard the discussion on the subject before the 
lorticultural Society, he feels no doubt on this head. The leaves, as well as the cut stems, of the manna 
Ash (Fraxmus Ornus) secrete, in like manner, saccharine matter. According to Treviranus, so do the upper 
surfaces of the leaves of Carduus arclioides during hot weather. (Darwin, in " Cross and Self-fertilization 
of Plants," p. 402.) 
HOMOPTERA. 
Cicadidce. 
(Cicadas, the " Locusts " of Australian boys.) 
Many of them pass parts of their life-cycles on Eucalypts; the entomologists 
alone can speak fully on the subject. 
From the following it would appear that the connection between manna and 
Cicadas is at least centuries old. See p. 102. 
The " Correspondence of John Ray " are letters from John Bay to Dr. Robinson, 
' and reply re the formation of manna by Cicadas in Italy, September, 1685. (Ray 
Society, 1848, 176 (already quoted). 
Now we come to Australia, and I cite writers with Australian experience. 
In " Discoveries in Australia " (J. Lort Stokes, i, 285-286, 1846), at Hobson's 
Bay, near Melbourne, the author says : 
The trees swarmed with large locusts (the Cicada), quite deafening us with their shrill buzzing noise. 
We found the branches of these trees and the ground underneath strewed over with a white substance 
resembling small flakes of snow, called by the colonists manna. I am aware that an erroneous idea exists 
that this matter is deposited by the locusts ; but in fact it is an exudation from the Eucalyptus ; and 
although I saw it beneath another kind of tree, it must have been carried there by the wind. A different 
sort, of a pale yellow colour, is found on a smaller species of Eucalyptus growing on highlands, and is much 
sought after for food by the natives, who sometimes scrape from the tree as much as a pound in a quarter 
of an hour. It has the taste of a delicious sweetmeat, with an almond flavour, and is so luscious that much 
cannot be eaten of it. This is well worthy of attention from our confectioners at home, and it may 
hereafter form an article of commerce, although from what has fallen under my own observation, and 
from what I have learnt from Mr. Eyre and others, I should say it is not of frequent occurrence. The first 
kind being found strewed underneath the tree, probably exudes from the leaf, whilst the second oozes 
from the stem. 
At Vol. II, 482, Mr. Bynoe, Surgeon to the Expedition, relates his experiences. 
Near Melbourne, I (Captain Stokes) again noticed the manna mentioned in a former page, but had 
no opportunity of making further observations upon it. Mr. Bynoe, however, having since visited 
Australia, has turned his attention to the subject, and the result of his experience, which will be found 
below, tends to overthrow the opinion I have previously expressed, to the effect that this substance is the 
exudation of a tree, not the deposit of an insect. 
Mr. Bynoe states : " There is a prevailing opinion in some parts of New Holland, particularly on the 
east side, that the gum trees distil a peculiar form of manna, which drops at certain seasons of the year. 
I have heard it from many of the inhabitants, who, on a close investigation, could only say that it was to 
be found adhering to the old and young bark of the trees, as well as strewed on the ground beneath. 
In the month of December, about the warmest period of the year, during my rambles through the 
forest in search of insects, I met with this manna in the above-mentioned state, but could never find in any 
p*art of the bark a fissure or break whence such a substance could flow. Wherever it appeared, moreover, 
the red-eyed cicada? were in abundance. I was inclined to think that the puncture produced by these 
suctorial insects into the tender shoots for juice, would in all probability give an exit for such a substance ; 
but by wounding the tender branches with a sharp-pointed knife, I could never obtain a saccharine fluid 
or substance. It was the season when the cicada 1 were abundantly collected together for reproduction ; 
