OF THE INTERIOR OF WESTERN AUSTRALIA. 259 
flowers, however, are quite different, and, indeed, a more extra- 
ordinary resemblauce in vegetative characters, resemblance not 
involving any protective function, has never come under my 
notice. Another of the new Myoporine®, Pholidia saligna, is 
treacherously like Myoporum platycarpum, R. Br., except as 
regards the floral characters. 
The frequent close resemblanee between certain species of 
Loranthus and their hosts was also noticed by me; nor was it 
without interest that I learnt, on my return home, how the same 
fact had been alluded to by that sagacious observer, James 
Drummond *, more than half a century ago. The two species 
showing this resemblance best are Loranthus pendulus, Sieb., var. 
parviflora, which is difficult to desery when growing upon the 
Quandong, and L. Quandang, Ldl, of which the leaves are 
strikingly similar to those of its host, an Acacia, But it may be 
doubted whether mere homoplasy is in point here, seeing that 
tle parasites are greedily eaten by camels f, and so are, in all 
-probability, equally attractive to vegetivorous marsupials. ln 
these cases, therefore, the resemblance may possibly be pro- 
tective, and may have been perfected by means of natural 
selection. The attraction probably lies in the flowers, which 
contain much neetar and are very sweet in consequence. 
It may also be mentioned that some Proteaceæ, Grevilleas and 
Hakeas especially, can scarcely be distinguished from Acacias 
when not in flower or fruit, 
Tue DISTRIBUTION or Desext Prants IN RELATION TO 
THE SOIL. 
Allusion has already been made to the prevalence of Myrtaceæ 
in certain distriets between Southern Cross and Siberia; and I 
propose now to describe briefly the peculiar flora found in the 
immediate neighbourhood of the large granite outcrops known as 
gnamma-rocks. The red soil, so common elsewhere, here gives 
place to soil of a pale-yellow colour, and this change is invari- 
ably accompanied by a change in the flora. 
* Hooker's Journal of Botany, ii. (1840) pp. 347 & 360. 
+ Camels will browse upon the parasites and leave the hosts quite untouched, 
although the latter are themselves excellent food. There would be stronger 
support for the suggested mimiery were the host distasteful; but the parasites 
have, it must be remembered, only a small range of selection, if any. 
