196 MERRILL. 
r 
the Archipelago a great number of plants of wide distribution 
in the Indo-Malayan region, which from their distribution and 
occurrence in the Philippines are certainly not indigenous spe- 
cies. Manifestly they must have originated in some other part 
of the Orient, and have been introduced into the Philippines, 
either within historic times, or at a still earlier date. It is only 
reasonable to assume that many of them have reached the Archi- 
pelago within the past 400 years. It is, however, practically 
impossible definitely to determine whether many of them have 
been introduced inadvertently by man, or by natural causes. 
Excluding the purposely introduced species enumerated above, 
and for the present ignoring those species of oriental origin 
having minute seeds, which in all probability have reached the 
Philippines through natural causes, there still remains a con- 
siderable list of weedy plants that presumably have been acci- 
dentally introduced, such as various grasses, Rotthoellia exaltata 
L. f., Apluda nutica L., Andr'opogon aciculattis Retz., Panicum 
flavidum Retz., Panicum distachyum L., Centotheca latifolia 
Trin., Eragrostis spp., certain sedges, and representatives of 
other families, such as Fleurya interrupta Gaudich., Cyathula 
prostrata BL, Aerua lanata Juss., Achyranthes aspera L., Por- 
tulaca quadrifida L., Nasturtium indicum DC, Aeschynomene 
indica L., Desmodium pulchellum Benth., D, triquetrum DC, 
D, gangeticum DC, D. lasiocarpum DC, Sesbania cannbina 
Pers., Crotalaria quinquefolia L,, C. linifolia L. f., Flemingia 
strobilifera R. Br., Pueraria phaseoloides Benth., Euphorbia spp., 
Phyllanthus spp., Sida spp., Abutilon indicum Don, Urena lobata 
L., Abelmoschus moschatus Moench, Merremia spp., Coldenia 
procumbens L., Moschosma tenuiflorum Heynh., Anisomeles 
indica 0, Ktze., Leucas spp., Leonurus sibirica L., Datura alba 
Nees, Vernonia patula Merr., Emilia sonchifolia DC, Sphaeran- 
thus africanus L., Grangea maderaspatana Poir., Erigeron lini- 
folius Willd., Wedelia prostrata Hemsl., Sonchus oleraceus L., 
and Crepis japonica Benth. 
While some of the above species may have been introduced 
by natural causes, by birds, or by winds, it is only reasonable 
to suspect that most of them, especially those species in genera 
having special adaptations for the dispersal of seeds by sticking 
to clothing, to the hair of animals, etc., have been introduced 
by man. In contrast to this, a large number of genera undoubt- 
edly owe their presence in the Archipelago to natural causes, 
their small seeds having been transported in one method or 
another by migratory birds, by winds, etc., as, for example, cer- 
