ix, c, 5 Gates: Pioneer Vegetation of Taal Volcano 405 
near the lake and to some of the delta! flats at the ends of stream 
channels. 
A third genetic series is very poorly represented in the waters 
of Lake Bombon surrounding the island. 
THE AQUATIC GENETIC SERIES 
This series in which aquatic plants tend to build up the bot- 
tom of a body of water is very poorly represented in the im- 
mediate vicinity of the volcano at the present day. Prior to 
the 1911 eruption it was present in the water around the island, 
particularly along the north coast. Along the coast of the main- 
land near Bahadero it is now plentiful and typical. 
THE VALLISNERIA ASSOCIATION 
The Vallisneria association, completely destroyed around the 
island by the eruption, reappeared within a year in the water 
along the western part of the north shore at the foot of bluffs. 
In December, 1913, the association was well represented along 
the coast at the foot of Mount Balantoc, by well-spaced, small, 
very red seedlings of Vallisneria gigantea. In most of the shel- 
tered coves along the north shore, broken leaves of this species 
are washed up on the shore. Four months later, the patch of 
Vallisneria had increased materially in size and density. In it 
were a few plants of Ceratophyllum demersum and plants of 
a floating aroid, Pistia stratiotes, caught by their leaves in shal- 
low water. At this time, there were cast upon the shore all 
along the north coast and about one-third way down the east 
coast quantities of Vallisneria , as well as plants of Ceratophyl- 
lum, Pistia and Lemna, and seeds of Sterculia foetida. The 
mechanical action of the water, however, was too great for the 
establishment of the association. A single small plant of Jus- 
sieua repens, a floating or rooted aquatic, was found in one of 
the sheltered bays. 
The associations which normally succeed this are entirely lack- 
ing. The transition between associations of the aquatic series 
and the marsh or dryland series is as yet noncontiguous. 
THE MARSH GENETIC SERIES 
This series of associations, inhabiting wet ground in progres- 
sively drier stages to dry ground, is clearly indicated in a few 
places on the island, but nowhere is well developed. For the 
most part, it occurs at the mouths of deep ravines on deltal 
flats which are formed just behind the low narrow shore ridge 
pushed up by the waves or in coves along the faces of bluffs. 
