588 Wisconsin Academy of Sciences^ ArtSy and Letters. 
where the wave lengths are shorter than 5500 a. The absorp¬ 
tion curves are in so close agreement in the region below 5800 a 
that no difference in color can fairly be attributed to differ¬ 
ences of absorption at that end of the spectrum. 
Fig. 12. Mean curves for lakes with marsh-stained waters: D. Dis¬ 
tilled water; 6. Beasley, Trout lakes; 8. Delavan, Geneva, Men- 
dota; 14. Nagawicka, Otter; 22. Oconomowoc, Okauchee, Wau- 
besa; 35. North lake. In this lake absorption at 4700 is .824. 
Table 6 
olor 
Lakes 
6___ 
Beasley, Geneva, Trout. 
8 ___ 
Delavan, Mendota. 
14__„ 
Nagawicka, Otter. 
18_-_ 
Lac La Belle. 
22 ___ 
Oconomowoc, Okauchee, Waubesa. 
35_ 
North. 
