432 
BOTANY. 
Lycopodium accompanied by any other tropical plant, which 
would indicate the aerial transport of larger objects than the 
microscopic spores of the Lycopodia.* 
The way plants have been dispersed is another interesting 
subject of enquiry. That minute spores of fungi are carried 
in the air to immense distances, is now an established fact. 
Professor Ehrenberg found the spores of fungi mingled with 
atmospheric dust that had fallen on ships far out at sea. 
That seeds are drifted by currents to great distances is also 
well known. American seeds are thus cast on the shores of Bri¬ 
tain ; and if those of considerable size are often thus conveyed, 
we may reasonably suppose others more minute would be so 
to a far greater extent. When resident in New South Wales, 
I could not help noticing, that the Australian coast flora was 
totally different from that of the interior, and far more 
abundant, and this also holds good with New Zealand. In 
Australia, the cedar is only found along the coasts, and not far 
inland; so likewise with the kauri in New Zealand. 
The fact also of the earth being filled with seed which 
retains its vitality for many ages, is also remarkable. I have 
noticed where lofty cliffs have fallen, and disclosed various 
ancient levels, that after a short time, the exposed vein of 
ancient vegetable mould has become covered with a vegetation 
of its own; so likewise when a portion of forest has been 
cleared and burnt off the ground, if suffered to remain un¬ 
cultivated, is speedily occupied by the Poroporo, an edible 
solarium. I observed a similar thing in Australia : where the 
eucalyptus forest has been burnt, it is succeeded by the 
mimosa; so also in North America, the primaeval forests are 
said to be replaced by the red cedar. 
The disappearing and reproducing of various plants in the 
same localities, is very remarkable, and seems to depend on 
certain conditions of soil and circumstances; yet it is doubtful 
whether indigenous plants ever disappear from their proper 
localities. When the spot they inhabit becomes possessed by 
plants or trees of hostile growth to the original inhabitants, 
* See Dr. Hooker’s admirable Introductory Essay to the flora of New 
Zealand; pp. xx. & xxx. 
