vations both on the geographical distribution and on some of the more remarkable points of structure of this order of plants. I shall now therefore confine myself to a few of the most important facts on each of these subjects.
Proteaceæ are chiefly natives of the southern hemisphere, in which they are most abundant in a parallel included between 32° and 35° lat., but they extend as far as 55° S. lat. The few species found in the northern hemisphere occur within the tropic.
Upwards of 400 species of the order are at present known; more than half of these are natives of Terra Australis, where they form one of the most striking peculiarities of the vegetation. Nearly four fifths of the Australian Proteaceae belong to the principal parallel, in which, however, they are very unequally distributed; the number of species at its western extremity being to those of the eastern as about two to one, and, what is much more remarkable, the number even at the eastern extremity being to that of the middle of the parallel as at least four to one. From the principal parallel the diminution of the order in number of species is nearly equal in both directions; but while no genus has been met with [568 within the tropic which does not also exist in the principal parallel, unless that section of Grevillea having a woody capsule[1] be considered as such, several genera occur at the south end of Van Diemen's Island which appear to be peculiar to it.
No Australian species of this order has been observed in any other part of the world, and even all its genera are confined to it, with the exception of Lomatia, of which several species have been found in South America; and of Stenocarpus, the original species of which is a native of New Caledonia.
The genera of Terra Australis that approach most nearly to the South African portion of the Proteaceae exist in the principal parallel, and chiefly at its western extremity; those allied to the American part of the order are found either at the eastern extremity of the same parallel or in Van Diemen's Island.
- ↑ Cycloptera, Lin. soc. transact. 10, p. 176; Prodr. fl. Nov. Holl. 380.
