Rickett—The Larger Aquatic Plants of Lake Mendota. 517 
bulk of the plant growth of the lake has not yet reached its full 
growth, while at this time Cladophora is at its prime. At this 
time, therefore, it forms a considerable part of the whole lake 
flora, while afterward it dies rather rapidly, and during the rest 
of the summer it is present only in small quantities. 
Comparison with Previous Work . Of the similar studies that 
have been made on lake floras, that on the vegetation of Oneida 
Lake, New York (1), is the most closely comparable. This lake 
is more varied in character than Lake Mendota, and a larger num¬ 
ber of aquatic plants are found there. There is more of the 
marshy type of shore vegetation, with numbers of emerged species; 
and the submerged plants are comparatively less abundant, none 
being found beyond the 6-foot contour. Mention is made, by the 
author, of several lakes in which the plant zone extends to greater 
depths. The problem of quantity in this study is approached 
from a different angle, the number instead of the weight of plants 
per unit area being determined, and the data used directly to cal¬ 
culate the animal population found associated with the plants. An 
exact comparison with the present study is therefore impossible 
from the data presented. 
Literature Cited 
1. Baker, F. C. The productivity of invertebrate fish food on the 
bottom of Oneida Lake, with special reference to mollusks. 
N. Y. State College For. Tech. Publ. 9. 1918. 
2. Birge, E. A., and Juday, C. The inland lakes of Wisconsin. Dis¬ 
solved gases of the water. Wis. Geol. and Nat. Hist. Survey 
Bull. 22. 1911. 
3. Jensen, P. B. jStudies concerning the organic matter of the sea 
bottom. Rept. Danish Biol. Sta. 22: 1-3 9. 1914. 
4. Muttkowski, R. A. The fauna of Lake Mendota—a qualitative and 
quantitative survey with special reference to the insects. Trans. 
Wis. Acad. Sci., Arts, and Lett. 19*: 374-482. 1918. 
5. Pammel, L. H. The vegetation of Iowa lakes. Rept. State High¬ 
way Comm, on Iowa Lakes and Lake Beds, pp. 162-189. 1917. 
6. Pettersen, C. G. J. A preliminary result of the investigation on 
the valuation of the sea. Rept. Danish Biol. Sta. 22 : 29-32. 
1915. 
7. Pond, R. H. The biological relation of aquatic plants to the sub¬ 
stratum. U. S. Fish Commission Rept. 1903: 483-526. 
