Ridley.—The Distribution of Plants. n 
countries in seeds of rice plants in the tropics, and vegetable and corn seed in 
temperate climates. Clement Reid has shown that a considerable number, 
including the Fumitories, Matricaria inodora , Linn., Centaurea cyanus , 
Linn., Euphorbia helioscopia , Linn., &c., occur with the Flax introduced by 
Neolithic man, and Poppies, Stackys arvensis , Linn., &c., first appear in 
Roman times. The Neolithic weeds are the earliest we have any record of. 
Many European weeds occur in the vegetable grounds of Tosari in Java, 
obviously introduced in the vegetable seeds from Europe. 
The rice-fields of the tropics contain also many species disseminated 
with rice-seed from other countries; such plants are Scirpus grossus , Linn, 
fil., and a number of other Cyperaceae and small Scrophularineae. 
By transport of cattle. 
Another method of introduction of weeds is by the transport of 
cattle. Large numbers of seeds of Grasses and other herbaceous plants are 
brought in the fodder, which with the dung is cleared out often on the fore¬ 
shore on arrival at the port, and the seeds frequently germinate and soon 
establish themselves. Amaranthi, Cleome viscosa , Linn., and Gynandropsis 
pentaphylla^ DC. (Capparidaceae), Herpestcs monniera , H. B. K., and Scoparia 
dulcis , Linn. (Scrophulariaceae), Panicum colonum , Paspalum conjugatum , 
and Imperata cylindrica owe their wide distribution largely to this cause. 
An interesting case of a cattle-dispersed plant is that of Clitoria cajanae- 
folia , Benth. (Leguminosae), a shrub with showy, pale violet flowers, which is 
a native of eastern Brazil, but is now abundant in Singapore, south Johor, 
and Sarawak, in Borneo. The pods contain a number of very viscid seeds 
which become readily attached to the hair of cattle browsing among the 
bushes, and are so transported from place to place. It is often to be found 
along cart-tracks where cattle pass constantly, but more usually where they 
are grazed. The plant seems to have been first introduced into Java, 
probably as an ornamental shrub, and then, borne by cattle, imported thence 
to Singapore, and later to Johor. Mr. Larkin, a planter, told me that it did 
not appear on his estate on the Tebrau river in Johor until cattle were brought 
there from Singapore. 
Another method of introduction is in the form of packing material, or 
by the attachment of the seeds or fruits to cargo, or in ballast on ships. An 
interesting example of this is the grass, Chloris barbata , Sw., probably 
indigenous in Africa, but now abundant in India, Ceylon, and South America. 
In Java and the Malay Peninsula it is quite confined to the regions of the 
docks and harbours, being abundant in these places in Singapore, Johor, and 
Province Wellesley, but it has not spread, so far as I have seen, 500 yards 
from these spots. The spikelets adhere by their awns to cloth. It occurs 
on sea-shores in Ceylon, and there seems no reason that it should not do so 
in the Straits Settlements, except that the soil in the neighbourhood of the 
