The Relation of Mollusks to Fish mv Oneida Lake 291 
In addition to supplying food material, plants perform 
another office, of nearly equal importance in many ways, that 
of providing support for animal food organisms, protection 
for breeding fishes, and a binding medium for the more or 
less shifting bottom material. As has been well stated by 
Petersen (1911), Pieters (1901), and J. E. Reighard 
(1894), the abundance of the larger plants is wholly depend- 
ent on the amount of shallow water wm the lake, and it has 
been noted that only in the shallow areas, called lake terraces. 
bordering the shores of the lake, do the plants find sufficient 
soil for attachment and lght and heat for their develop- 
ment. There is an intimate interrelation between plants 
and this shallow area, the latter forming the necessary 
depth and soil while the former, with their extensive root 
system, hold the soil in place and prevent excessive erosion, 
In Oneida Lake it is noteworthy that there is a wide zone of 
water, 1 to 6 feet in depth, bordering the shore, which is 
especially well developed in the w estern end, and that coin- 
cident with this shallow area there is a luxuriant growth of 
vegetation. ‘The bottom soil is mostly sand or boulders, mud 
feme reduced to a few small spots, and the plants are 
mostly of the types living in a sandy soil. The development 
of Bulrushes and Water Willow, therefore, is significant. In 
Lake Erie, Pieters (1894, p. 15) noted that the plants dis- 
appeared when the water reached a depth of fifteen feet, and 
were scarce in water ten feet deep. The same relation of 
plants to depth was noted in Oneida Lake. Deep lakes do 
not have an abundant development of vegetation and so far 
as the abundance of life is concerned, are comparable to land 
deserts. 
The zonal arrangement of plants in some of the habitats is 
noteworthy. These are described in Chapter IT under Field 
Stations. The plants listed in the following pages form 
but a small part of the vegetation living in and about the 
lake. Those species mentioned are intimately connected with 
the animal life, hence their selection from among the large 
number of species present. The majority of the species have 
been identified by Dr. Wm. L. Bray of the Department of 
