papers on biology and agriculture 217 



bog while all other parts of the lake are relatively shal- 

 low. 



Another feature of interest is a small island or patch of 

 floating mat which is forming very rapidly about 300 

 yards off the center of the bog. It appeared about five 

 years ago and was at first only a few yards across. In 

 1922 it was L shaped, each arm being about 20 yards long, 

 but it is not yet solid enough to bear a man's weight. The 

 plants are mostly sedges with some Decodon verticillatus, 

 a very important mat-forming shrub. (Fig. 4.) 



At the other extreme of maturity is the bog near Wau- 

 conda already described (4 — No. 4) and one near Antioch 

 in S. E. corner, Section 15, T. 46 N., R. 10 E., about three 

 miles southeast of Antioch. The Antioch bog occupies a 

 small, almost circular depression about 300 yards in di- 

 ameter with a relatively narrow swamp zone on the north, 

 east and west, but with a long flat valley on the south. 

 The shrub zone is narrow, and consists chiefly of choke- 

 berry and winterberry with some red ozier dogwood, 

 swamp blueberry and elder. The tamarack forest is 

 very mature with solid substratum and large trees, and 

 there are also several upland specimens present, includ- 

 ing a yellow birch 10 inches in diameter and several red 

 or ellipsoid oaks, and occasionally choke cherries, trem- 

 bling aspens and mountain ashes ; and one service berry 

 was noticed. (Fig. 5.) 



The undergrowth is most mesophytic in the eastern 

 half of the forest with few bog relicts, but including 

 Maianthemum, Trientalis, Smilax, Geum, Onoclea sensi- 

 bilis, Osmunda regalis, Asplenium sp., but in the western 

 half there are fair sized patches of sphagnum, a few 

 pitcher plants, and one specimen of menyanthes was ob- 

 served. The east side is more open, many tamaracks 

 have been overturned or cut, and there are few shrubs 

 except red ozier dogwood which was abundant locally. 

 There is a wide swamp zone on this side with quite 

 abundant dwarf birch. Although the substratum is dry 

 in autumn, the drift material in the bushes indicates 

 temporary water levels of 2 to 3 feet above the surface in 

 times of heavy precipitation, probably in the spring. 



