366 George E. Nichols, 



patches locally. Along the margin of the swamp is a fringe of 

 swamp forest. Floristically the vegetation of this swamp 

 resembles in many respects that of an ordinary well-drained 

 swamp. The majority of the vascular plants present there are 

 also represented here, but they are relatively much less abundant. 

 Myrica Gale is perhaps the commonest shrub in the open part of 

 the swamp, and there are present here three shrubs not previously 

 listed : Pyrus arhutifolia atropnrpiirea, Rhamnus alnifolia, and 

 Loniccra caerulca. The boggy nature of the swamp is suggested 

 by the presence of such plants as the two species of Scirpus 

 mentioned, Rynchospora alba, Smilacina trifolia, Sarracenia 

 purpurea, Vaccinmm Oxycoccus, and Lobelia Kalmii, as well as 

 by the luxuriant growth of the sphagnums. The dissimilarity 

 between this swamp and a bog is emphasized, among other things, 

 by the presence among the marginal woody forms of Taxiis 

 canadensis, Acer rubrum, Fraxinus americana and F. nigra. 



Viewed from a genetic standpoint, it seems apparent that the 

 area formerly occupied by the swamp vegetation was much more 

 restricted than that which it occupies to-day. Originally long 

 and narrow, as the surface has become built up through the 

 accumulation of peat the swamp has spread out laterally, 

 encroaching on the adjoining forested areas. Evidences of quite 

 recent encroachment were noted just above where the swamp 

 crosses the road. Among the pioneer seed plants, to judge from 

 a relict colony near the lower end of the swamp, were Calama- 

 grostis canadensis, Juncus brevicandatus, and Iris versicolor; but 

 the upbuilding of the surface and the lateral expansion of the 

 swamp have been largely attributable to the luxuriant growth of 

 the sphagnums and of the two sedges, Scirpus hudsonianas and 

 S. caespitosus. It may well be said that the nature, and indeed 

 the very existence, of the swamp as it is to-day is closely 

 correlated with the activity of the compact mass of peat thus 

 formed and of the superimposed plant cover in obstructing the 

 drainage and thereby conserving the water supply. 



Swamps B and G. — Swamp B, from a genetic standpoint, may 

 be regarded as representing a later stage in the developmental 

 series than swamp A. Conditions in swamp B have been more 

 favorable to peat accumulation than in swamp A, owing to the 

 more level nature of the terrain, and over much of the area the 

 deposit of peat is more than six feet thick. It will be noted 



