1920] | Wherry,—Soil Tests of Ericaceae and Other Families 43 
var. obtusata, Moneses uniflora, Ledum groenlandicum, Chamaedaphne 
calyculata, Chiogenes hispidula, and Vaccinium Oxycoccos. In addi- 
tion to Ericaceae, there occur on the sphagnum Arethusa bulbosa, 
Listera cordata, Microstylis unifolia, Dalibarda repens, Cornus cana- 
densis, Menyanthes trifoliata, and Linnaea borealis var. americana, 
a typical acid-soil list. By way of contrast, on the same trip, the 
other species of the orchid genus Microstylis, M. monophyllos, was 
found, near Harvey's Pond, growing in spring water with minimalka- 
line reaction. 
FAIRLEE, VERMONT. 
The hills to the west of Lake Morey, near Fairlee station, yielded 
further interesting results. No arbor-vitae swamps occur here, but 
there are several swampy spots in the deciduous woods, where the 
water, emerging from shale strata, is neutral to minimacid in reaction. 
In this water were found the orchids, Cypripedium hirsutum (reginae), 
Habenaria psycodes, Habenaria (Limnorchis) hyperborea, H. dilatata, 
H. dilatata var. media, Habenaria (Lysiella) obtusata, Microstylis 
monophyllos, Liparis Loeselii, and Corallorrhiza trifida. In drier 
places, where the acidity is mostly subacid, were observed also Cypri- 
pedium parviflorum var. pubescens, Habenaria (Lysias) Hookeri, 
H. orbiculata, H. macrophylla, and Habenaria (Coeloglossum) bracteata. 
Several ericaceous plants accompany these orchids in the dry or 
damp woods, their soil being an upland peat more or less neutralized 
by the underlying glacial drift, so that the acidities are unusually 
low for several species; those noted comprise: Pyrola americana, P. 
chlorantha, P. elliptica, P. secunda, Chimaphila umbellata, Epigaea 
repens, Gaultheria procumbens, Vaccinium pennsylvanicum var. angusti- 
folium and V. canadense. These gave tests of subacid to minimacid 
reaction. 
DATA ON INDIVIDUAL SPECIES. 
In order to summarize the data for each species above noted, and 
to bring out their acid and alkaline limits of growth, some mode of 
graphic representation is desirable. For this purpose the specific 
acidities are best ranged horizontally, and the acidities at which the 
plant has been observed to grow, being marked by x, and the “opti- 
mum,” at which the species appears to thrive best, distinguished 
by a capital X. The letter o refers to data obtained by the writer 
elsewhere in natural habitats, and n is used to indicate observations 
