Marshall—The Vegetation of Twin Island. 785 
Betula lutea Michx. 
Aralia nudicaulis L. 
Sanicula marylandica L. 
Taenidia integerrima (L.) Drude 
Cornns candidissima Marsh. 
Cornus alternifolia L. 
Galium horale L. 
Galium triflorum Michx. 
Diervilla diervilla (L.) MacM. 
Sambucus puhens Michx. 
Helianthus hirsutus Raf. 
Solidago canadensis L. 
Aster exiguus (Fernald.) Rydb. 
Aster macrophyllus L. 
Achillea millefolium L. 
Habalus albus (L.) Hook. 
VEGETATION OE THE STRAND. 
In contrast with the center formation, the strand presented 
less than half the number of species, but a much greater number 
of individuals for a unit area. The smaller number of species 
is partly accounted for by the much smaller area; hut in part 
by the fact that, as this zone is subject to inundations of water 
in the early part of the season, the number of woody plants will 
he small and the number of herbaceous plants limited to those 
species that can grow rapidly and mature in late summer and 
fall. At this season conditions are most favorable for them, 
as has been pointed out. On the south-west side of the island 
where the strand is widest and runs into the marsh, this fact 
was well illustrated by the great luxuriance in late August; 
plants nearest the center grew rank and flowered, while the re¬ 
treating water was followed up by a dense growth of seedlings. 
It was interesting to notice the very early stage at which many 
of these tiny plants, marigolds and mints, began to bloom. 
Among the larger herbaceous plants were found Joe-pye weed 
(.Eupatorium purpureum L.), marsh St. John’s-wort ( Triade - 
nmn virginicum (L.) Raf.), two knot-weeds (Polygonum 
amphibium L. and P. lapathifolium L.), two loosestrifes 
