352 



cent regions. It was only a few meters in width, and in 1894 

 and 1895 it was frequently necessary to clear it of encroaching 

 vegetation in order to make feasible the 30-meter oblique haul. 

 In high water and generally in years subsequent to 1895 it was 

 only necessary to avoid with drawn net or pump the clumps of 

 Ceratophyllum which still dotted the bottom in this neighbor- 

 hood. The point of collection thus lay at all seasons towards 

 the narrowing end of the lake and in the path of the current 

 maintained by Quiver Creek and the marginal springs. At 

 times of high water it was in the direct path of the downward 

 current of impounded backwaters thrust towards the channel 

 by the encroaching eastern bluff (PI. II.). 



At times of flood the invading river waters extend for some 

 distance, even to the middle of the lake, crowding the clearer 

 lake waters to the eastern side. When the western bank was 

 not submerged the backwaters entering by way of the chutes 

 sometimes reached the plankton station. Our collections were 

 always made in evident lake water unless otherwise stated 

 (Table V.). 



The access of creek and spring water, the extensive areas 

 of dense vegetation, and the shoal waters, which at all levels 

 form the greater part of the area of this lake, all combine to 

 make the temperature conditions subject to great local varia- 

 tion, and to diversify the fauna and flora indigenous or adven- 

 titious in the plankton of this body of water. 



COLLECTIONS. 



Our chronological series in this lake includes 115 collections, 

 extending from June 6, 1894, to March 28, 1899. The collec- 

 tions in the several years number 14, 13, 31, 24, 26, and 7 re- 

 spectively. Their distribution by months is shown in the table 

 between pages 342 and 343. In the earlier years the interval of 

 collection was somewhat irregular, though with 6 exceptions 

 every month is represented. From July, 1897, collections were 

 made at least every fortnight and on the same day as at the 

 other stations. The oblique-haul method was used — with a few 



