538 
APPENDIX. [Botany of Terra Australis. 
nation of Dicotyledones takes place, until in about 60° N. lal and 55° S. lat. 
they scarcely equal half their intratropical proportion. 
In conformity with these results the Dicotyledones should be to the 
Monocotyledones of Terra Australis as nearly 9 to 2 ; whereas the actual 
proportion as deduced from our materials is hardly 7 to 2 : but it appears, 
on arranging these materials geographically, that the relative proportions 
of the different regions of Terra Australis itself, are equally at variance 
with these results. About half the species of Australian plants at present 
known have been collected in a parallel included between 38 and 35° S. 
lat. ; for this reason, and for one which will hereafter appear, 1 shall call 
this the principal parallel. At the eastern extremity of this parallel, within 
the limits of the colony of Port Jackson, where our materials are the 
most perfect, the proportion of Dicotyledones to Monocotyledones does 
not exceed 8 to I. At the western extremity of the same parallel, in the 
vicinity of King George’s Sound, the proportion is but little different from 
that of Port Jackson, being nearly as 13 to 4. At the south end of Van 
Diemen’s Island in 43° S. lat., it is fully 4 to 1. And with this proportion 
that of Carpentaria, and I may add the whole of the sequinoctial part of 
New Holland, hitherto examined, very nearly agrees. 
I confess I can perceive nothing, cither in the nature of the soil or cli- 
mate of Terra Australis, or in the circumstances under which our collections 
were formed, to account for these remarkable exceptions to the general pro- 
portions of the two classes in the corresponding latitudes of other countries. 
With regard to the proportion of Acotyledones in Terra Australis, 
it is necessary to premise that I consider my collections of some of the 
Cryptogamous orders, especially of Fungi, as very imperfect. If, however, 
300 species were added to the 400 actually collected, I believe it would 
give an approximation to the true proportions, which on this supposition, 
would be of Phsenogamous to Cryptogamous plants as nearly I L to 2. 
But the general proportion of these two great divisions, as deduced from 
the published materials, is very different from this, being nearly 7 to 2. 
If we enquire in what degree these proportions are dependent on cli- 
mate, we find that in the more northern parts of Europe, as in Lapland and 
even in Great Britain, Cryptogamous plants somewhat exceed the Ph;u- 
