Denniston—The Larger Aquatic Plants of Lake Mendota. 497 
grows more abundantly on clay bottoms. Castalia and Nymphaea 
appear to prefer a mur bottom. West (2) found Castalia speciosa 
growing equally well in mud or sand in the Scottish lakes. 
The Potamogetons, Elodea, Myriophyllum, Najas, and Vallis- 
neria grow apparently as well in mud as in sand. Upon the rocks 
no flowering plants were found. Only an alga, Cladophora, was 
present. 
In University Bay a strip of Scirpus lacustris extends along a 
bar about 200 meters from shore; behind this bar are found 
Ranunculus aquatilis, Nymphaea advena, Castalia odor at a, Lem- 
na minor, Lemma trisulca, Ceratophylhcm demersum, Myriophyl¬ 
lum verticillatum var. pectinatum, Vallisneria spiralis, Wolffla 
Columbiana, Elodea canadensis, Najas flexilis, and five species of 
Potamogeton. 
Another station where plants were found in abundance and 
variety was at the outlet of Pheasant Branch Creek (station 10), 
at the west end of the lake. Here a few plants of Potamogeton al- 
pinus were found and also Utricularia vulgaris, in addition to the 
same species found in University Bay, with the exception of 
Wolffia which was not found at this station. 
A sand bar extends for fully 1600 meters across Catfish Bay. 
This is exposed in one small area only. In all other places ex¬ 
cept at the channel, the water covers the bar to a depth of from 
5 to 60 centimeters. There is a passage or channel through the 
bar near the east end, where the bottom drops suddenly to a depth 
of a little over 5 meters. In this deep hole were found Cerato- 
phyllum demersum, Najas flexilis, and Vallisneria spiralis grow¬ 
ing on a mud bottom. 
In the bay between Maple Bluff and the State Hospital (sta¬ 
tion 28), there was a considerable accumulation of dead vegetable 
matter which prevented the growth of vascular plants near the 
shore. The same was true to a less extent opposite Morris Park 
(station 19). 
The prevailing summer wind from the southwest keeps this 
matter in the bays at the north side of the lake fairly constantly. 
On days when there is little wind, the odor from this decaying 
vegetable matter is very disagreeable. In certain Scottish High¬ 
land lakes (3) great quantities of dead vegetable matter accumu¬ 
late and prevent the growth of water plants both near shore and 
in deeper water. In these lakes, however, there is no unpleasant 
odor, as the plant remains are preserved from decay by the pres- 
32—S. A. L. 
