MacMillan: shores at lake of the woods. 999 



1. A floating bog comes to have a redistribution of its com- 

 ponent plants so that if it has been long separated from the 

 shore where it was formed it no longer shows the longitudinal 

 vegetation-striae of the old zonal morassic shore but develops 

 a zonal grouping of its own. The peripheral areas are there- 

 fore specialized from the central and a group of plants estab- 

 lished at the water's edge, able to bear the lapping of the 

 waves and enjoying the higher illumination, may be distin- 

 guished. At the center of the island shrubs or even small 

 trees may become established and the whole bog, if it were 

 not for the next condition to be observed would be character- 

 ized by a series of zones very plainly marked, but not the old 

 zones of the original shore. 



2. A floating bog drifting about in a bay from one shore to 

 the other, touching at different points and frequently exposed 

 to the strong winds in the middle of the bay, while in transit 

 from bank to bank, becomes a resting place for numerous 

 varieties of light seeds. Furthermore, while temporarily situ- 

 ated at one spot or another on the shore, it is, to some extent, 

 colonized by the plants of that region and thus from both con- 

 ditions its number of species of established plants tends to rise. 

 Hence, floating bogs of long standing are scenes of very sharp 

 struggle for existence among a considerable number of alien 

 plants. This has a tendency to obscure both the original and 

 the secondary zonal distribution and to a marked degree the 

 floating bog will partake of an azonal character in consequence. 



3. The undulating movement communicated to the bog 

 when exposed to wave action loosens somewhat its'langled 

 network of roots and decayed organic substance so that the 

 texture of the soil is modified from that of the general type 

 of attached morass to which it originally belonged. This 

 change in texture brings about a slight change in plant popu 

 lation. Hence floating bogs are usually rich in Sparganiaceae, 

 Typhaceae and Carices which develop under such conditions 

 with considerable vigor. 



4. The presence of the lake water underneath every part of 

 the formation keeps it cool and moist beyond what is possible 

 for attached morass. This again has its. modifying influence 

 upon the plant population. 



These mechanical, biological and other conditions are quite 

 sufficient to give to the floating bog a population distinctively 

 its own. While belonging to the main subdivision of shores to 

 which the name morass is given, it does not, especially if its 



