The South Australian Naturalist. 



25 



roots ceases to operate, and Avith the cessation of respiration 

 the production of carbonic acid stops. A crust of limestone at 

 once forms about the roots, and produces the root-moulds so 

 commonly found in the white dunes along- the shore. The trees 

 Avhich gveyv in the ancient red sands were evidently smothered 

 ]^v nn ii-.vfi«inn nf flip vnimo-pr «iAnd duiips. The strouo' sea 



CalciHed trunks of trees in the old red sand dunes at Fulhani. In the 

 central foreground is a Idackfellow 's chipping stone used in the making 



of spear heads. 



1 ^~ici Lc iiyj y\ 



This operation may be witnessed during the spring and early 

 summer months on Eucalyptus saplings and on gum trees that 

 have been cut down and sprouted again. Pick out a tree that 

 is swarming v.^ith ants, and you will probably find a number of 

 the froghopper larvos feeding upon it ; they Avill very seldom be 

 found alone, but in the company of one or more ants, who are 

 busily at work milking, in their ovrn way, their "cows," 



