ITO 
SPICES 
CHAP. IV 
their ends a number of short arms, usually from 3 to 9 
in number, all nearly equal in length. At the end of 
each arm, which is abruptly decurved, is a yellow 
rounded body, the zoosporangium. These zoosporanges 
open by a minute hole at the top and let out a number 
of zoospores, which swim in drops of water by the aid 
of two minute hairs or cilia^ and are thus carried 
from leaf to leaf by the rain, and probably also these, 
or another form of zoospore, are dispersed while in the 
resting stage by wind. 
The pest was identified for me by Mr. Massee as the 
alga Cephaleurus my coidea, Karsten [My coidea para- 
sitica, Cunningham), which is known as a destructive 
parasite on many kinds of thick-leaved trees, in the 
Straits Settlements, Malay Islands, and Ceylon. It 
attacks among other trees camellias, tea,- mangosteen, 
and similar trees. Full accounts of it are published 
in the Transactions of the Linnean Society, 1880, by 
Cunningham ; by Karsten in Annales du Jar din 
Botanique de Buitenzorg, vol. x. p. 24 ; and by 
Marshall Ward {Trans, Linn, Soc,, 1881, vol. ii. p. 87). 
The plant forms a kind of crust, the thallus, on 
the leaf, and pushes down root-like processes into the 
tissue of the leaf, destroying it, apparently mainly by 
using up its water supply. The leaves turn yellow and 
fall sooner than they should, giving the tree a bare 
appearance. Many of the boughs are leafless nearly to 
the top, and the whole appearance of the tree is weak 
and shabby, with scanty foliage. Some trees in the 
Botanic Gardens at Singapore were badly affected by 
this alga, and the treatment of washing them with 
Bordeaux mixture was tried with marked success. 
The mixture was syringed on to the trees with a 
bamboo squirt till the foliage was conspicuously blue. 
At the next putting forth of leaves it was noticed that 
the young leaves which came out were not attacked by 
the parasite, while the trees that were not syringed were 
as bad as before, the leaves being all spotted with the 
fungus, and many buds blackened and dead. 
