Lake Maxinkuckee, Physical and Biological Survey 303 



or less by waves, and supplement the work of the seeds in distrib- 

 uting the plants. Both seeds and flowers are inconspicuous ob- 

 jects. In spring the buds, when they begin growth, show marked 

 heliotropism. 



Apparently in some places at least, these plants retained more 

 or less activity, as well as form and color, throughout the winter. 

 Generally above the apices of the plants under the clear ice there 

 were large bubbles frozen into the ice, and toward the latter part 

 of the winter, especially above a patch down by Norris Inlet, there 

 were crossing and recrossing curves of rows of fine bubbles, like 

 strings of minute beads, suggesting that the plants had been ex- 

 haling small bubbles of gas, perhaps oxygen, the winter long and 

 the moving plant tips, swayed perhaps by moving currents, or in 

 all probability following the circle of the sun, had left behind a rec- 

 ord or graph of their gyrations. The hornwort appears to be one 

 of the most active oxygenators of water we have. In window 

 aquariums on bright days during winter, when the sun shines in 

 on these plants, one often sees a rapid succession of minute bubbles 

 form a line from leaf tips of these plants to the water surface, the 

 bubbles breaking at the surface in rapid succession with an audible 

 lisping sound and a minute dash, of spray. It is not certain that 

 all these bubbles are oxygen formed during the ordinary processes 

 of photo-synthesis in the plant, as in some cases bubbles are given 

 off rapidly from broken bits of stems. 



FAMILY 54. CABOMBACE^:. WATER-SHIELD FAMILY 



329. WATER-SHIELD 



BRASENIA SCHREBERI Gmel. 



Rare in Lake Maxinkuckee^ the only patch in that lake being 

 near the green boathouse in the vicinity of Norris Inlet. It is 

 fairly abundant in Lost Lake and there are a few plants in the old 

 bayou (a remains of the old channel or thoroughfare) west of the 

 railroad. It blossoms very rarely here. The leaves take on beauti- 

 ful hues in autumn, The young leaves down close to the rootstock 

 remain green all winter. It starts up early in spring ; small leaves 

 were seen near the bottom of Lost Lake May 3, 1901. Green leaves 

 were washed ashore November 3, 1904. 



The plant is peculiar in having its stems and flower-stalks 

 coated in a clear gelatinous substance so that it appears as if en- 

 cased in glass. 



