METROXYLON. i 157 
to the chalaza, into the substance of the albuman, which presents in that 
place a deep suborbieular cavity; the surface of the seed, divested of the integu- 
ment, is even, and not pitted; the albumen is homogenous, bony, and, in a vertical 
section through the embryo, horse-shoe shaped ; embryo basal. 
Metroxylon is a very natural genus, not allied to any other, and well characterized 
by its arboreous habit, by the terminal definite inflorescence, and by the flowers in 
pairs, moncecious, externally similar, and densely arranged in cylindrical spikes. Its 
nearest ally may be considered to be the calamoid genus  Korthalsía, which has 
also the flowers similarly approximate in spikes, but solitary, and really hermaphro- 
dite, at the axilla of every spathel or bract; whereas in Metroxylon the flowers, 
although similarly placed, are ‘in pairs and coliateral. one of each being a male 
and the other a female or seeming hermaphrodite. With Pigafetta, Metroxylon 
has in common only the arborescent habit, for the first is a dioecious plant, with 
flowers quite different in the two sexes, and, on the whole, widely different from 
those of Metroxylon. 
H. Wendland in the erroneous belief what Metroxylon had a i provided 
with ruminate albumen, a belief caused by the false representation of the seed of 
Sagus genuina Labill in Turpin’s “ Dictionnaire des Sciences naturelles, Botanique ” 
proposed the genus Coelococcus for Sagus vitiensis, which has indeed a seed with 
homogeneous albumen, excavate in its upper part, but which in no way differs from 
that of the typical Metroxylons. There-is therefore no reason for keeping Colococcus 
distinct as a genus from Metroxylon. (About the rumination of the seed of 
Metroxylon, see my observations under M. Rumphi var. buruensis). 
The fruit of Metroxylon contains normally only one seed; once, however, I found 
2 seeds in M. squarrosum var. Kilkarua. 
The two best known species of Metroxylon, M. Rumphii and M. Sagus, which 
indeed are barely distinet as species, present numerous varieties growing wild, but 
more frequently eultivated, in the Moluecas, and especially in Amboina and in Ceram. 
At my request, prineipally with the intention of obtaining a precise identification of 
the varieties of Sagus described. by Rumphius, the authorities of the Botanic 
Garden of Buitenzorg have most kindly procured me specimens of numerous varie- 
ties of Sago palms growing in the Moluccas, aud specially in Ceram: Notwithstanding 
this valuable help, I have not succeeded in identifying with certainty all the 
varieties mentioned in the ‘ Herbarium Amboinese,” or in giving precise characters 
for the new ones; such diffieulty, however, is always encountered with species that 
have been long in cultivation, and have produced numerous varieties. 
* Ihave made an accurate study of the different species of Metroxylon, and espe- 
cially of M. Rumphi, and have consequently been able to give a description more 
complete of that important genus than any yet published, and to make corrections 
of several gross errors, which have been traditionally transmitted from one author 
to another; such correctigns more especially are that Metrozylon has a seed with 
homogeneous, and not ruminate albumen; that the flowers are not polygamous, nor 
hermaphrodite, but moncecious and proterandrous on the same spike, viz., that the 
female flowers are apt to be impollinated after all the male flowers have disappeared, 
and finally, as I have already demonstrated above. that there is no reason to consider 
Ceelococeus as distinct from Metroxylon. 
