American Fisheries Society 123 



The portion of Kawaquesaga where we took our specimens 

 has been characterized in a recent paper (Trans. Wisconsin Aca- 

 demy of Sciences, Arts, and Letters. Vol. 16; p. 18). It is 12 

 to 18 meters in depth, of rather irregular outline, and an area 

 of about 2.5 square kilometers. Its surface temperature in Au- 

 gust is about 20 degrees C,, while the bottom temperature is 

 about 9 degTees C. As we descend the oxygen becomes gradually 

 less until at about 10 or 11 meters it disappears entirely. It was 

 only to corroborate a natural supposition that we fished below 

 this depth and caught nothing. But wlien we set our nets at 8 to 

 10 meters, where oxygen still occurs, only in about one-tenth 

 the amount found at tlie top, we caught Tullibee in abundance 

 and of a weight up to three pounds. From here it ranges up- 

 ward to within 3 or -1 meters of the surface ; at the surface it- 

 self it does not seem to appear. 



Xorth Twin Lake at Hackley is of about the same depth as 

 Kawaquesaga, but its area is much larger and more fully ex- 

 posed to the wind. Hence while the surface temperature is 

 about the same as in Kawaquesaga, the temperature at the bot- 

 tom is higher, or about 11 degrees C. The decrease in oxygen 

 is not quite so rapid either, and there is some left even at the 

 l)ottom, or one-half m. al)ove it, although only somewhat less 

 than one per cent of wliat there is at tlie top. Yet here it is in 

 the lowest meters of water that we caught Tullibee abundantly, 

 and more were taken in shallow Avater. 



Ijong Lake is of a different character from either of these 

 lakes. It is long and narrow, curved enough so that the effect 

 of the wind is at least partially checked, and of great depth, 

 especially for its widtli : 26. o meters were found near the north- 

 ern third of its length. (It is to be noted that this is not one 

 of the two lakes of the same name, referred to in ]\Iarch's Table 

 of Lakes. Wis. Geol. and Xat. Hist. Survey, Bulletin Xo. XII ; 

 p. 88.) It is fed in largest part by springs and its narrowness 

 from east to west and forested shores protect it somewhat from 

 the warming effect of the sun; vegetation in it is rather scant, 

 except at the lower end, which is shallow. Consequently the 

 usual cause for the consumption of oxygen at the bottom is 

 largely absent, and one-half as much oxygen occurs here as at 

 the top. The bottom temperature is low, only about four or 



