a he 
‘The History of the Flora from the Jurassie Period to the Present Time: General. 395 
it is generally assumed, that there is a possibility of their being conveyed by 
wind, or even birds, across wide stretches of ocean, especially in the case of 
sporiferous species. But even with these latter, the spores of a plant, inhabi- 
ting only a windless forest-interior, could never be the sport of the wind. 
The case of Hymenophyllum ferrugineum of Juan Fernandez, Chile and New 
Zealand is hard to explain on the supposition of wind-carriage and equally 
difficult is that of 77. Malingü, an epiphyte, of quite local occurrence, on the 
trunks of certain Taraceae or Pinaceae in New Zealand and Tasmania, but 
absent on neighbouring dicotylous trees. Were spores as readily ABER by 
the wind, as is supposed, there should be no special fern-floras, which is not 
the case’); nor should the endemic Polypodium novae-sealandiae be confined 
to one portion of the North Island of New Zealand, since it ascends to the 
subalpine belt. Regarding the seed-plants, the RE evidence already 
given concerning the distribution of alien species in New Zealand, 
in every way for travel and ecesis, and their relation to the ana 7e =t ur 
tion, shows how exceedingly difficult it is for a plant to gain SRIEREE into : a “ : 
virgin plant-formation. 
Ecesis, rather than the possibility of bird-carriage &c. during iong a : 
of time, is the great stumbling-block. Transoceanic dissemination may rightly- 
be evoked as an explanation of the presence of Australian, Polynesian and 
even Northern species in the fact of migratory birds from the first two regions ee 
5 e carriage of seeds and even cryptozoic animals, on trees 
brought to the sea by flooded rivers, seems the most feasible method of travel 
for many species. The indehiscent seed-pod of Be might Ion preserve 
main 
