188 BOTANICAL GAZETTE [MARCH 
figured in geological works. Hundreds and sometimes thousands 
of these miniature dunes may be seen in a single landscape. 
Arctostaphylos Uva-urst and Juniperus Sabina procumbens age dune — 
formers within moderate limits. Both of these shrubs are pro- 
cumbent creepers, and hence unable to rise above the sand to 
any considerable height, probably never as much as a mele 
above their original position. It is for this reason that such 
hardy plants as these cannot grow successfully on an uppe — 
beach that is exposed to extensive sand drifting. The above — 
three species are the most prominent dune-formers in protected 
places. Arctostaphylos dunes occur throughout, and are no! 
confined to fossil beaches, but are also common on ex 
heaths. The Andropogon dunes were not seen except on fossil 
beaches, although this grass is common along the entire coast. 
The Juniperus dunes occur chiefly northward. 
The dune formation seen on east coasts was chiefly of ths 
small, slow-growing, secondary type. The dunes at Waukega 
in part at least, are formed by Juniperus. On the east shore of 
Beaver and North Manitou islands, there are a numbef of low 
dunes formed conjointly by Juniperus and Arctostaphylos. a 
ee INR re ey Oe Se ee 
are low slow-growing Juniperus dunes on the shore of Foust 
lake on Beaver island; in addition to the procumbent yo 
Juniperus communis and Gaylussacia resinosa assist in dune bu 
ing here. The Andropogon dunes are better develop 
ed on the | 
. int 
fossil beaches of North Manitou island than at any other pol 
mae : oe 
visited. On these same fossil beaches, Hudsonia tomentosa ee 
On the east 
in a small degree to collect the wind-blown sand. 
shore of North Manitou island, the pasture grass, Lie -_ 
forms miniature dunes. es 
Near the beach at South Chicago there are swampy sa a 
sions tenanted by Potentilla Anserina and Polygonum sent ftet 
plants which are best developed in low grounds Bie wer 
creep up to higher levels. On these higher levels €4! ee 
they collect the drifting sand and are able to form low ising 
similar to Arctostaphylos. These plants show 4 noe eee 
plasticity, since a single individual developed in a er 
