219 



(Rhus venenata), the second by blue flag (Iris versicolor) and the third by 

 sedges. The Rhus belt contains a very little sphagnum, a few pitcher 

 plants, and some droseras. These are plainly remnants of a condition 

 similar to that which maintains at present in the tamarack ai'ea. Besides 

 these there are sedges (E'riophorum Virginianum), swamp bellfiower (Cam- 

 panula aparionoides), and a few mints (Mentha Canadensis, and Lycopus 

 sinuatus). 



The Iris Zone. — The blue flag (Iris versicolor) gives the color to this 

 zone, but there are nearly as many individuals of marsh shield fern 

 (Asplenium thelypteris) and bonset (Eupatorium perfoliatum) as of Iris. 

 These were the predominant plants, but there appeared a smaller number 

 of goldenrods (Solidago Canadensis), meadow sweet (Spirea salicifolia), 

 trow-weed (Yernonia Noveboracenous), horse-mint (Monardo fistulosa) 

 agrimony (Agrimouia pariflora), and vervain (Verbena hastata). The 

 mints and composites seem to be the most prominent among the fore- 

 runners of mesophytic life. Outside this was a fragment of a sedge belt. 

 This contained coarse sedges and grasses (Scirpus atrovirens S. microcar- 

 pus, S. cyperinus, Panicum Crus-galli) and a few composites. 



The north side (Fig. 9) is like the west except that there is no sedge 

 zone, the Iris of the east end is x-eplaced by calamus (Acorus calamus)^ 

 and the Rhus almost disappears as the eastern extremity is approached. 

 Tavo species, however, should be noted. On the inside of the Rhus zone 

 two individuals of thistle (Cnicus lanceolatus) were found. These are. 

 as it were, the extreme advance guards of xerophytic conditions. About 

 the center of this zone, several individuals of Sagittaria (Sagittaria vari- 

 abilis) in a healthy condition were found. So far as I am able to dis- 

 cover, this plant is never introduced except in water. This means that 

 this plant has been able to sui-vive the changing conditions from lake 

 margin to Rhus belt by gradual adaptations. These plants were much 

 smaller and contained less chlorophyl than plants of the same species 

 growing in water at the same latitude. 



The South Side. — The south side contains one of the primary drain- 

 age lines. Along this an open ditch has Teen dug. The willows (Salix 

 nigra, S. alba, S. discolor, S. tristis, ST Hicida, S. cordata) follow the ditch 

 throughout its entire length. Near the tast end the roses (Rosa Carolina) 

 form a belt reaching from the deciduous forest trees on the south to the 

 tamaracks on the north. North of the ditch they follow the ditch to its 

 western extremity, but the zone becomes narrower. Toward the west a 



