Oceanic Dispersal of Pandanus ■ — STONE 
of plants. The name mentioned by Kanehira 
"arowan,” is a general term used to designate 
any wild (i.e., nonedible) Pandanus or its fruit. 
The word is apparently of Marshallese origin, 
where the preferred spelling is "edwaan” ( the d 
rolled like an rr) . The other two islets of Mokil 
were not seen, so there is no corroborative infor- 
mation regarding the Kanehira collection. There 
seems no reason, however, to doubt Kanehira’s 
data, and it is assumed that the specimen is in- 
deed from Mokil. 
The specimen consists of several phalanges, 
or keys, of the fruit. The configuration of the 
carpels which, fused, make up each phalange, 
determine the section of the genus, and the pe- 
culiar "focussed” pattern, as pointed out by St. 
John (I960) in his discussion of section Intra- 
oh tutus, is apparent. Although somewhat smaller 
than Martelli’s description and figure indicate, 
the Kanehira specimen appears to be referable 
to Pandanus pistillaris Martelli. This specks,, and 
in fact the section itself, is known only from 
Melanesia, specifically, from the Bismarck Archi- 
pelago. Similar species, and a closely related sec- 
tion ( Lateriobtutus St. John) occur in New 
Guinea. 
In December 1957 the author observed spe- 
cies of these sections — in particular, P. pistil- 
laris — in their native habitats in New Ireland 
and New Britain. The trees are characteristic of 
lowland areas, although they may occur at alti- 
tudes of 300 m. or more. Frequently they are 
found along streams, and not uncommonly, near 
the coast, especially (as near Kavieng, New Ire- 
land) on limestone. Phalanges which had fallen 
from these trees were occasionally seen as drift 
along the stream estuaries and along adjacent 
beaches around Kavieng and northwestern New 
Ireland. In this area, a considerable variation in 
fruit size was observed, much more than is indi- 
cated by Martelli’s description; because of this, 
and the above factors, the Kanehira specimen, 
without much hesitation, can be placed as P. 
pistillaris. 
If this is established, it is interesting to con- 
sider the possibilities for drift. One obstacle is 
our meagre knowledge of the full, natural range 
of P. pistillaris; there seems, however, to be lit- 
tle question that, if it is not actually endemic in 
the Bismarck Archipelago, it is restricted to that 
611 
general area. From a study of the excellent charts 
provided by Schott (1939) and by Wyrtki 
(1957), it may be seen that a strip about 5 to 
7° north of the equator and east of the 140° 
meridian, during both seasons of the year, is 
characterized by a more or less constant eastward 
flow, which in northern winter emanates from 
the Mindanao-Morotai region, and in northern 
summer emanates also from a strong current 
moving westward and slanting northward along 
the upper edge of the Melanesian area, but re- 
versing its course in the Mindanao-Morotai re- 
gion. The northern summer current spans a 
wider course along the equator, reaching nearly 
all of the Caroline Islands ( except perhaps Palau 
and Yap) and proceeding possibly beyond the 
Marshalls. During this season, the route of a 
drifting object starting from New Britain or in 
that vicinity would be westward along the north- 
ern coast of New Guinea as far as Morotai, 
thereafter more or less directly eastward through 
Micronesia. During northern winter, counter 
currents forming a strong oceanic stream along 
the northern coast of New Guinea would pre- 
vent such a route of drift, while several minor 
whorl systems in the area bounded by the Ad- 
miralty Islands on the west and by the Solomons 
on the east would make the drift pattern irreg- 
ular and unpredictable, possibly even somewhat 
southward. The actual number of miles and the 
elapsed time at sea must remain a matter of con- 
jecture. No information is available as to the 
length of time over which floating phalanges 
may be viable; but indirect evidence (cf. Ed- 
mondson, 1941, for data on viability of coco- 
nuts after ocean flotation) appears to indicate 
that distances of 1,000 mi. or more are possible. 
Thus it may be seen that the route of drift of 
an object afloat near the Bismarck Archipelago 
might, by the devious route outlined, terminate 
in Mokil Atoll or others of the Caroline Islands. 
Corroboration of such a route is available. Both 
Riesenberg ( 1959) and Sinoto ( I960) have re- 
ported New Guinea canoe prows washed ashore 
in the Marshall Islands. Riesenberg (personal 
communication) has photographs of an entire 
canoe in the Marshalls which apparently drifted 
along this same route. Sinoto describes a New 
Guinea canoe prow which drifted to Nukuoro 
Atoll. 
