508 AUSTRALIAN INDIGENOUS HUMAN FOOD PROVIDING PLANTS, 



77. Eucalyptus dumosa, A.Cunn., N.O. Myrtacese, B.Fl., iii., 

 230. 



Lerp, Larp, Laap, or Larap Eucalypt. 



This shrub yields a kind of manna called Lerp or Larp by the 

 aboriginals. It is the nidus of an insect, and consists of starch, 

 which is eaten in summer by the aborigines of the mallee 

 country. It somewhat resembles in appearance small shells ; 

 it is sweet, and in colour white or yellowish-white. According 

 to Dr. Thomas Dobson, of Hobart, the insect which causes the 

 lerp to form is Psylla Eucalypti. 



It is probably formed on the leaves of other Mallee Eucalypts. 



"This substance occurs on the leaves, and consists of white 

 threads clotted together by a syrup proceeding from the insect 

 (Psylla Eucalypti) which spins those threads. It contains, in 

 round numbers, of water 14 parts, thread-like portion 33 parts, 

 sugar 53 parts. The threads possess many of the characteristic 

 properties of starch, from which, however, they are sharply 

 distinguished by their form. When lerp is washed with water the 

 sugar dissolves and the threads swell but slightly, but dissolve to a 

 slight extent, so that the solution is coloured blue by iodine. The 

 threads freed from sugar l)y washing consist of a substance called 

 Lerp-amyhim. 



" Lerp-amylum is very slightly soluble in cold water, not 

 perceptibly more so in water at 100°, but entirely soluble to a thin 

 transparent liquid when heated to 135° in sealed tubes with 30 

 pai'ts of water ; this solution on cooling deposits the original 

 substance in flocks, without forming a jelly at any time. The 

 separation is almost complete. 



" If the material employed in this experiment were entirely free 

 from sugar, the licpiid left after the separation of the flocks will 

 also be free from sugar. The flocks deposited from solution are 

 insoluble in boiling water , therefore lerp-amylum suffers no 

 chemical change on being heated to 150° with water. Heated in 

 the air-bath to 190° while dry, it turns brown, and is afterwards 



