EUCALYPTUS VIMINALIS. 



and leaves) of E. viminalis yielded in one experiment performed in the author's laboratory 5 Ibs. 

 1 oz. crude potash, which after purification gave 2 Ibs. 14 ozs. carbonate of potassium ; one ton of 

 dry stem-wood yielded 3 Ibs. 2 ozs. crude potash, which after purification gave 1 Ib. 13 ozs. 

 carbonate of potassium. See Eeport of the Melbourne Botanic Garden 1869, p. 15. 



The real and special interest of Eucalyptus viminalis is concentrated in the fact, that it is 

 this particular species, which mainly, if not almost solely, furnishes the Mellitose-Manna. That 

 Cicadas are instrumental in the formation of Mellitose-Manna from Eucalyptus viminalis was 

 noticed long ago by many an observant early colonist. Dr. George Bennett, F.R.C.S., F.L.S., 

 C.M.Z.S., already in the meritorious volume on his " Wanderings in New South Wales," p. 321 

 (1834), relates, that the Manna exudes in minute drops from the bark of what he very significantly 

 called Eucalyptus mannifera in a state of syrup-consistence and then concretes ; he adds, that it 

 oozes out, forming thin flakes upon the trunk, and that when secreted from the branches it may 

 fall upon the leaves beneath or upon the ground. Previous rains and subsequent heat, he says, 

 promote the flow, the time of exudation being about midsummer. The great geographical explorer, 

 Captain Start, also in one of his works spoke already of the occurrence of the Eucalyptus-Manna, 

 where the large Cicada} abounded, on observation confirmed by many observers, and in Tasmania 

 by Mr. S. H. Wintle, who remarks, that these insects have been most numerous, when the Manna 

 has been most abundant. 



It is the great Cicada rncerens (described by Germar), which has been identified by Professor 

 McCoy, F.R.S., as connected with the Mellitose production (see McCoy's Natural History of 

 Victoria, Decade v. 50). In a letter, written to me in September 1879, he traces the Mellitose-flow 

 also to the action of Cycloclieila Australia, likewise fully described and brilliantly figured in the 

 Decade quoted above and published in 1880. Dr. G. Bennett in his " Gatherings of a Naturalist 

 in Australasia," p. 270-273, alludes also to these and allied Cicada; or Tettigoniaj. 



An experienced entomologic observer in Tasmania, Mr. Aug. Siuison, wrote to the author in 

 October 1879 and May 1880, that "lie had seen near George's Bay trunks of E. viminalis with 

 streams of so-called Manna adhering to them even to near the base ; it was exuding from perfora- 

 tions of the bark, made by Cicada moerens ; hundreds of these insects were on the trunk, with their 

 boring organ buried in the bark. This borer is about half an inch long, tubular and very slender, 

 and terminates in a saw, with which they pierce the bark at right angle to their body, the whole 

 length except the short broad base going into the bark ; through this apparatus they suck up 

 the sap. They are easily caught when their boring organ is thus buried in the bark, as they 

 cannot withdraw it rapidly. In its larval stage it lives underground, presumably on roots ; there 

 also it becomes a pupa, much the same in form as the perfect insect minus the wings. When 

 ready to emerge it comes out of the ground, nearly always in early morning, and ascends the first 

 object it comes across. There it fixes itself by the claws of its frontlegs ; the case splits up along 

 its back, and the insect escapes, withdrawing its limbs singly from the enveloping case. The wings 

 in a very short time attain their full dimensions and become of proper consistency, though soft at first, 

 and the insect flies away." All this is much in accord with many other insects. He saw " hundreds 

 of these Cicadas come up, where the ground had been cleared of ferns and timber, and they had to 

 climb stems of grasses or of small herbs in full sunshine, so that they got their wings or their case 

 dried up, before they had quite escaped ; consequently could not liberate themselves, but became 

 prisoners in their pupa-case, half in, half out, shortly afterwards to be attacked by ants and to be 

 devoured." Eucalyptus-Manna occurs, however, also in the South of Tasmania, where the large 



