46 HORN EXPEDITION NARRATIVE. 



tlie catoi-pillur just wlion it l)ogins to clirysalato, and in which the chrysalis lies. 

 As wn have seen tlie social Central Australian cateipillars como out of their 

 counnon case, eacli one goes into the ground and there chrysalates. In the case 

 of Metura the house is used iirst hy the caterpillar, and subsequently by tlie 

 chrysalis, but even here it is not to be regarded as equivalent to, or even taking 

 the place of, the cocoon, as the larva when passing into the chrysalis stage makes a 

 rough kind of cocoon for itself inside the outer case. The latter, in fact, may 

 always be regarded as a structure connected with the larva or caterpillar stage, 

 and the cocoon as simply connected with the pupa or chrysalis stage. 



The scrub over all this part of the country was characteristic of the general 

 scrub of the steppes in the Finke basin south of tlu^ I'anges — that is one which is 

 formed of a mi.xture of s'arious kinds of plants, and not made up mainly of one 

 kind as in the case of Giddea, Mulga or Malice sciub. 



Amongst the shrubs and trees four genera were dominant — Eucalypts, Acacias, 

 Cassias, and Eremophilas. 



The Eucalypts away from the I'iver beds arc usually of the species known as 

 malice gums — with no tall central .stem, but with a number of thin ))ranches 

 spiinging from a stem which projects, at most, for only a short distance al)ove the 

 ground. Tiu^y giow in patches, but are nothing like so plentiful in this as in other 

 parts of Australia, where dense malice scrub will stretch monotonously over mile 

 after mile of country. 



Tlie Acacias vary in size from a few feet to twenty or' thirty in height ; as a 

 general rule they have thin harsh petioles ser-virrg as leaves ; their genervil tint as 

 in the case of the Mulga is a dull depressing olive green, though at times, Acacia 

 saliciiia will grow into a tree with denser and greener foliage, sometimes hanging 

 gr-a,cefully dowir as if it were a weeping willow. This is really the most attractive 

 tr'ce in the scrul), and often the only one ben(>ath which any shade can be obtained 

 when the sun is shining in a brilliant clouilless sky, and the strong light is I'cflected 

 fr'om the hai'd yellow ground. 



The Cassias only grow into good sized shrubs, perlrajis at most, si.\- or eight 

 feet high. Their leaves as a general rule are thin and their br-;ui('lies straight and 

 wiry, l)ut still they often form green patches which, covered with masses of yellow 

 l)lossom, ser've to br'ighten the didl scrub. 



Often for' miles together the gr'cater number of the Cassias are dead, and their 

 thin wiry br-.anches all S])ringirig togelbei' from w short stem cloF.e above the gr'ound 



