1899] DUNE FLORAS OF LAKE MICHIGAN — 175 
fossil beaches and terraces, its scattered bunches or tufts form- 
ing one of the chief landscape features. 
On the more northern fossil beaches several species are almost 
as characteristic as those named in the preceding paragraph. 
Prominent among these forms are Zygadenus elegans, Campanula 
rotundifolia arctica, and Arenaria Michauxii; northward these 
types are almost wholly confined to the fossil beaches or terraces, 
although Zygadenus is sometimes present on the upper beach. 
Anemone multifida, Keleria cristata (?) and Aradis lyrata occur 
northward but are less frequent. A very interesting plant which 
sometimes frequents fossil beaches is Hudsonia tomentosa, a species 
noted for its habit of forming scattered clumps of densely 
tufted growths. Other occasional tenants of the terraces and 
fossil beaches are Populus monilifera, Prunus pumila, Calamagrostis 
longifolia, and Solidago nemoralis. 
While the fossil beach looks backward to a true beach history, 
commonly looks forward to a heath. Largely protected from 
the accumulation of sand, they furnish a situation favorable for 
ne development of a juniper-bearberry heath. Such heaths are 
0 process of formation at Manistee, North Manitou and else- 
Where, and will be described in another place. 
B. THE EMBRYONIC OR STATIONARY BEACH DUNES. 
1. Dunes of rapid growth (primary embryonic dunes). 
ol the lake winds which blow across the beach Pave a sur- 
and car rene and are able to select out the finer grains of sand 
Sasi igs farther from the shore. The action of the wind in 
ae picked ree analogous to that of water. The finer particles 
are blown bodily by the air currents, while the larger particles 
Peed along on the beach. Whenever an obstacle 
Or all of the load is necessarily deposited by the 
foarser particles are deposited upon or about the 
le the finer particles form a diminishing trail on the 
Soon as the deposition is sufficient to relieve the over- 
ne trailing of sand ceases, and the wind continues 
ned load until another obstacle isreached. So long 
ss met, SOme 
Wind, The 
obstacle, whi 
lee side. < 
With 
Its lesse 
