114 BOTANICAL GAZETTE [ FEBRUARY 
reach of the waves, and yet is unoccupied by dunes or other 
topographic forms. 
1. The lower beach. 
The lower beach has been defined as the zone of land washed 
by the waves of summer storms. It might almost be defined as 
that portion of the beach which is devoid of vegetation. Per 
haps there is no flora in the temperate zone quite so sparse as 
that of the lower beach, unless we except bare rocks and alkaline 
deserts. A survey of the life conditions in this zone reveals at 
once the reason for the scanty vegetation. Land life is excluded 
because of the frequency and violence of storms; the waves teat | 
away the sand in one spot only to deposit it in another. Evel 
though a seed had the temerity to germinate, the young plant 
would soon be destroyed by the breakers. Nor is there great | 
likelihood that seeds will find a lodgment in this unstable loca 
tion. As will be seen later the seeds ripened by tenants of the 
middle beach are almost entirely scattered away from the lake 
instead of toward it. The action of both wind and wave tends | 
carry seeds away from the lower beach. Again, few seeds could 
endure the alternate extremes of cold and heat, wetting and dry- 
ing so characteristic of this zone. 
Water life is excluded because of the extreme xerophytt 
conditions which commonly prevail on the lower beach. While 
alge may propagate themselves in the shallow pools or even # 
the wet sand during a prolonged season of wet weather, 4 ae : 
tion of activity if not death itself soon follows the advent of dt 
weather. During a period of rainy weather in the autumn” | — 
1897 green patches were observed in wet sand a few mete? 
from the mouth of a creek near Porter, Ind. Microscopic seg 
vation showed that the green coloration was due to the pr" 
of millions of motile Chlamydomonas forms. These unicel 
biciliate algze were in process of active locomotion in the es 
held by capillarity between the grains of sand. In all prob oe 
these forms migrated to the beach from the waters of the nigh 
during a period of wet weather. It is possible that they 
pass into resting stages and live through a season of Ne 
