i REPORT OF COMMISSIONER OF FISH AND FISHERIES. 147 
no young individuals having been observed. Moreover, the dead and 
diseased fishes had been feeding almost exclusively on a red insect 
larva peculiar to the mud of the deep water, while all the healthy fishes 
observed had been feeding on shallow-water forms. 
The mortality, thus, seems to have been limited to the perch that 
were ranging in the deeper parts of the lake in company with the dis- 
eased herring, and observations indicate that such a deep range for 
_ the perchis unusualin midsummer. There also seems to be a deficiency 
in Lake Mendota of the kinds of animals usually selected by the perch 
as food, according to observations made elsewhere. A heavy flooding 
rain which occurred not long before the outbreak of the disease may 
have washed into the lake unusual quantities of organic matter from 
the swamp beyond Catfish Bay and from the surrounding country. 
- Quite similar cases of destruction of the native fishes are of rather 
common occurrence in the rivers of Illinois in the hottest weather of 
the year. They usually, if not always, follow upon floodin g rains, and 
thus occur when the streams are full or overflowing with turbid water 
loaded with the products of decay. 
During the summer of 1890, Prof. C. Dwight Marsh, of Ripon Col- 
lege, began a physical and biological examination of Green Lake, 
situated in Green Lake County, Wis., for which the Fish Commission 
supplied one of its deep-sea thermometers for takin g bottom tempera- 
tures. His investigations will be continued during the summer of 
1891, when he expects to publish an account of his results. 
Be, Cag Ege 
INDIANA. 
The investigations begun in Indiana by Prof. B. W. Evermann in 
1888 were continued by him during the summer of 1890 in the northern 
and western parts of the State. Considerable work was done at inter- 
vals in the vicinity of Terre Haute, both in the Wabash River and in 
the numerous ponds which occur along its course in this region. Dur- 
ing the regular spring rise in the river these ponds fill with water and 
numerous fishes enter at the same time, but in the summer and early 
autumn many of the ponds become dry, and great numbers of fishes 
perish there in consequence. Among the Species which are thus de- 
Stroyed are the black bass and crappie, and other valuable food-fishes. 
Several hundred specimens in good condition were transplanted to 
Lake Maxinkuckee by Prof. Evermann. Observations and collections 
were also made at Bonebank and Mackey Ferry on the lower Wabash 
River and at several places in the St. J oseph River basin, as follows: 
Pigeon River, Twin Lakes and Cedar Lakes near Ontario and Lima; 
Oliver Lake at Valentine, and Elkhart River at Goshen. Material 
was likewise obtained at Plymouth from the Yellow River, a tributary 
of the Kankakee, from Lake Maxinkuckee, and from the Tippecanoe 
River, a few miles south of the lake. Prof. Evermann was assisted in 
his work by anumber of his students at the State Normal School, Terre 
