354 Ridley— On the Dispersal of Seeds by Wind. 
the contrary it is probably on an average nearly twice as long. If this is 
so it follows that the family must be of great antiquity, as must also be the 
forest-region which most of the species now occupy. 
As it is impossible that the fruits of these trees can cross the sea in 
good enough condition to germinate, even if they ever reached the sea or 
could grow on the sea-shore when stranded, it follows that the whole area 
occupied by them must have been connected by dry land when they 
migrated, whether from Cambodia to the Philippines, or Borneo or 
Sumatra ; but at what period this was we cannot even surmise. 
Shorea macroptera , Dyer. A tree about 70 feet tall grows in a wood 
near the house. It is evidently an old tree, as it is partly hollow. It is 
a smaller species than 5 . leprosida , and fruits rather earlier ; a tree planted 
in 1884 is now fruiting, though only about 30 feet tall. The furthest fallen 
fruit I can find is just 40 yards from the tree, and the only seedlings not 
further than 20 yards. This tree well overtops the rest of the surrounding 
wood, and is in a well-exposed position, so that it gets the full force of 
the wind. 
The wood has grown up on ground evidently cleared at some period, 
with only a few of the original forest trees left, including the Shorea. The 
whole of the trees, as far as I can see., are those whose seed is regularly 
distributed by birds, bats and civet cats, together with stray fruit trees, 
planted, or seedlings from fruit grown or eaten near the house. 
Another tree about 30 feet tall in jungle had the greater part of its 
fruit lying just beneath it, and nearly all destroyed by mice ; but I found 
a few seed about 30 yards away from it in the jungle. 
Shorea gratissima , Dyer. A tall tree, about 80 feet high, growing in 
a wooded part of the gardens, fruits tolerably regularly more or less each year, 
but often dropping a year or two. The most distant fruits were found about 
1 6 yards from the base of the tree. These fruits are five-winged, but three 
wings are larger than the other two. It flies less well than Shorea leprosida. 
Shorea rigida , Brandis. A very large tree in the jungle, with trees 
as tall surrounding it. The fruits fall about 20 yards at the furthest, and 
young trees are to be seen about the same distance from the parent. Trees 
planted in another part of the gardens about twenty years ago are still 
quite small. 
Anisoptera costata , Miq. Tree over 60 feet tall in jungle. It fruits 
more or less every year, but only in quantity once in five years. It 
flowered this year, but I could only find one fruit. The fruit is large, with 
broad wings and heavy ; surrounded by jungle the greater part of the fruits 
fall within 6 yards of the trunk, and the furthest young trees I can find 
are within 15 yards of the parent tree. 
The Dipterocarpeae, at least almost all the species with winged fruits, 
inhabit only dense forests far from streams by which the migration of the 
