242 On a New Sjwcies of Manna 



manifestly differs in all its properties. This was the first 

 manna examined Avhich contained no mannite ; and I have 

 now to add to the list another, similar in this respect, hut 

 diifering- in every other, and peculiarly remarkahle from its 

 possessing a regularly organised structure. 



The specimen suhjected to analysis I owe to the kindness 

 of Mr. Sheriff Cay, hy whose son, Mr. Robert Cay, the 

 substance was originally discovered in the interior of 

 Australia Felix, to the north and north-west of Melbourne. 

 An immense tract of country in this district is entirely 

 occupied by a " scrub," as it is called in Colonial language, 

 consisting of the mallee plant, Eacalyptus dumosa, the 

 leaves of which at certain seasons become covered with this 

 species of manna, which is known to the natives by the 

 name of Lerp, the / being pronounced like the Italian gl. 

 This substance was first observed by Mr. Cay in the latter 

 part of the year 184d, when he explored a considerable 

 district lying between lat. 3G° 20* and 37° 10' S., and long. 

 142° 40' and 144° 20' E., in search of pasturage for sheep. 

 He returned in 1845 to occupy the ground, and in the 

 course of his journey was obliged to leave his party, in 

 pursuit of a native guide who had decamped with a gun. 

 In mentioning this incident, Mr. Cay writes (25th March 

 1845) : "I was rather cold that night, as I had come off 

 after him in my shirt-sleeves ; moreover, I had no dinner, 

 but I got plenty of lerp. Lerp is very sweet, and is formed 

 by an insect on the leaves of gum-trees ; in size and appear- 

 ance like a flake of snow, it feels like matted wool, and tastes 

 like the ice on a wedding-cake." 



On Mr. Cay's arrival in Scotland in 1847, he gave some 

 further particulars regarding this substance, stating that it 

 was produced in great abundance, and covered large tracts 

 of the scrub-like snow ; that it is very nutritive, the natives 

 becoming fat during the season in which it is found, and 

 that he himself had subsisted for a day or two upon it ; that 

 it adheres with very little tenacity to the leaves, and is 

 immediately washed off by a shower of rain. 



As it appeared from this description that the substance 

 was unknown in this country, Mr. Cay, at his father's 

 request, wrote to his overseer in Australia, who sent over 

 the quantity of lerp which has formed the material for my 

 observations, accompanied by a letter, dated 25th February, 

 1848, of which the following is an extract : — " The Blacks 

 say the lerp is not in any way produced by an insect, but 



