56 Rhodora [Marcu 
New Brunswick and Maine where the noncalcareous rocks are deeply 
buried in Pleistocene marine clays the Cedar is often found. The 
very great difficulty of deciding off-hand in a drift-covered area 
whether a given colony of plants is in a caleareous or a non-caleareous 
soil has already been referred to in a quotation from Chalmers. This 
difficulty is made clear by the following incident. The argillaceous 
rocks which occupy much of the lower valley of the Penobscot are 
essentially non-calcareous. Yet at a few points, such as the ledges 
near the ferry at Veazie, there occur good developments of Arbor 
Vitae, accompanied by such well-recognized calcicolous herbs as 
nemone canadensis, A. riparia and Juncus brachycephalus, species 
which abound in the limestone region of Aroostook County but which 
are exceedingly local on the lower Penobscot. The present writer 
called this area to the attention to one of his friends at the University 
of Maine, a prominent chemist and mineralogist, who, after visiting 
the spot and taking rock-samples, reported that the rock itself was 
non-calecareous but that when tested with acid the surfaces gave 4 
marked effervescence. Further study of the region showed that at 
this point along the river the ledges were stained by seepage from the 
steep banks of an esker which follows the valley, and that the caleareous 
waters from the esker had here converted the non-caleareous rock into 
a definitely caleareous habitat. sine 
imilarly, a small vein of calcite intruded into an otherwise non- 
calcareous rock will materially effect the neighboring soil, while trap 
dikes, which are commonly calcareous, often alter the soil-conditions 
delight in truly calcareous soils are not to be expected. ee 
point we have the clear statement of the great soil-chemist, Hilgard: 
“A soil-formation overlying limestone on the slopes of a range may 
be wholly derived from non-calcareous formations lying at 4 a 
elevation, or may have been leached of its original linn : 
abundant rains. The feldspars constituting rocks designa’ es 
granite, may or may not be partially or wholly of the soda-lime sand 
of the potash series; the mica may or may not be partially rep the 
by hornblende, in which cases the soil would be calcareous ‘ 


