XII, C,4 Brown, Merrill and Yates: Volcano Island 215 
_ the above plants appear to be specially adapted for dispersal 
by floating. Owing to the short distance from the mainland if 
is probable that many other seeds having no special adaptation 
for floating have reached the island by this means. Some, which 
by themselves cannot float at all, may have been carried by 
floating drift. This is particularly true, since in a short time 
the fresh water would not impair the germinating power of the 
seeds. It is a well-known fact that most of the seeds of tropical . 
weeds will not float and this is apparently true of most species 
with minute seeds. This fact, however, does not preclude the 
possibility that some of these plants may have been transported 
by the last-mentioned method. 
The heading “organs for adhering” includes those seeds and 
fruits with hooks and spines, barbed or viscid hairs, or other 
special adaptation by which they adhere to the fur of animals, 
the clothing of man, or the feathers of birds. Hyptis swaveo- 
lens, a most successful weed, falls in this group on account of 
the gelatinous viscid covering of the wet seeds. 
Under the heading “eaten by animals” are placed those plants. 
eaten by cattle and which may be disseminated by such seeds as 
are not digested. Most of these seeds are minute and very hard. 
It is probable that some species have thus reached Volcano Island, 
and it is certain that a number of them have been disseminated 
over the island by this means as a considerable number of cattle, 
carabaos, and horses range on the island. 
_ Under the heading “man” are included those species that are 
usually disseminated only or chiefly by man. Annona reticulata, 
custard apple; Arachis hypogaea, peanut; Bambusa spp., culti- 
vated bamboos; Ipomoea batatas, sweet potato; Oryza sativa, 
rice; Manihot utilissima, cassava; Musa sp., banana; and a few 
others are found on the island. 
Under “minute seeds” we have placed a large number of 
‘species—characteristic fresh-water plants, rice-paddy weeds, 
and others—which are for the most part of very wide geographic 
distribution; but whose seeds usually do not float, are not 
adapted for dissemination by the wind, and yet are most suc- 
cessful emigrants. Many, if not most, of these are distributed 
through the medium of mud, in which the seeds are imbedded 
‘in large numbers, adhering to the feet and coats of birds and 
other animals. ‘ 
There are a number of species—some of them are very wide 
distribution and abundant in all tropical countries—that we have 
not succeeded in classifying according to the method by which 
