198 Fortieth Annual Meeting 



diminution in numbers of these midge larvae for we found 

 them very abundant in all bottom samples taken in this 

 habitat; and as mentioned, they were still being eaten by 

 the suckers. It is possible that whitefish prefer plankton 

 food but took midge larvae on account of a scarcity of this 

 early in the season, but no data to show such a seasonal 

 increase in amount of plankton were obtained. Investi- 

 gations along this line should certainly be incorporated in 

 future work on any of these small lakes where whitefish 

 thrive. The small minnows referred to, which formed such 

 large schools near the surface of deep water, were being 

 eaten, to some extent at least, by wall-eyed pike, for the 

 large specimen of this species taken in August at the time 

 these minnows were so numerous contained several of them. 

 Perhaps the presence of these little fishes over deep water 

 was due to an abundance of plankton on which they were 

 feeding. If so, their large numbers would make them a 

 strong factor in the destruction of whitefish food; and the 

 wall-eyed pike, in this respect, would be related to the white- 

 fish as a benefactor. A study of the food and habits of 

 minnows when they are numerous in a lake where whitefish 

 live might yield some practical results. 



2. THE PONDWEED ZONE 



The pond weed zone is a belt of submerged plants extend- 

 ing around the entire lake in water from about 5 to 25 feet 

 deep. Although the pond weeds {Po tamo get on) were the 

 most prominent plants here, others, principally Cliara, 

 Myriophyllum, Ceratophylluyn, and Naias, were present with 

 them in large numbers. From collections made and by 

 observing from a boat, it was very evident that the pond- 

 weed zone was the region of most abundant and varied fish 

 life in the lake. Perch were numerous and certainly out- 

 numbered all species except those belonging to the family 

 of minnows, which was represented in this zone by several 

 species, two of which, the blunt-nosed minnow (Pimephales 

 notatns) and the straw-colored minnow thickly populated 



