6 JAMES MURRAY 



the smaller ones melted in summer it was seen that it formed continuous sheets over 

 the whole bed of some of them. Everywhere microscopic life swarmed on this weed. 

 The method of collecting during the winter was very simple. A few pieces of ice 

 containing plants were chipped out and taken to. the house to thaw. When quite 

 melted the weed was put into a coarse silk net, which was again put inside a very 

 fine silk net, and the whole immersed in a bucket of water. When the nets were 

 violently shaken in the water the microscopic organisms, animal and vegetable, were 

 washed off the weed, and strained through the coarse net into the fine one, from 

 which they could be easily transferred to a bottle. Thus were obtained multitudes 

 of living things for study. 



In summer the collecting was still simpler. The weed could be washed in the lake 

 water without the need for preliminary thawing. 



In this way we collected continually from the shallow lakes. There were some 

 deeper lakes, which, as it proved, did not melt in summer. In Clear Lake a hole 

 was dug through the ice. We came on water at a depth of about four feet. Here 

 we dredged on the lake bottom, at a depth of seventeen feet. There was a quantity 

 of vegetation brought up, but it was discoloured and dead, and there was no living 

 thing upon it. 



Late in the winter, Priestley sunk a shaft in the southern portion of Blue Lake, 

 for the purpose chiefly of observing the temperatures of the ice. At a depth of nine 

 feet some scraps of weed were got, and when thawed a number of living animals 

 were found on it. At a depth of fifteen feet we came on the bottom of the lake, 

 which was here composed of angular fragments. These were covered by a continuous 

 film of yellow weed, and on this also there were numerous living things. 



In autumn an attempt was made to use the tow-net in some of the lakes. The 

 lakes being at this time covered by a thick sheet of ice, the net could not be drawn 

 through the water. A hole was dug and some gallons of water taken up with a 

 bucket and poured through the net. At this time the temperatr" of the air was 

 about Zero Fahrenheit, and the net was soon filled with ice. When thawed out 

 there was no living thing found in it. In summer, when the lakes were melted, and 

 the air temperature was about freezing-point, the tow-net could be easily used, and 

 good collections were got. 



The vegetation of these lakes is so important a feature in the biology of the district 

 that it merits some attention. Portions of it have been submitted to expert botanists, 

 but no report has yet been received, so it cannot be stated to what group of the 

 vegetable kingdom it belongs. Its appearance and method of growth will be described. 



In Green Lake and many other lakes it is in the form of sheets, from a few inches 

 to many yards in extent, sometimes continuously covering the bed of a pond from 

 side to side. It varies in thickness, from one-eighth to half an inch or more, and is 

 of a consistency like sodden paper, so that it was not possible to lift up sheets of any 

 considerable size without breaking them. The upper surface is of a bright orange 



