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gradual the series of variations, that it seems as though names 
can be regarded merely as conveniences for indicating certain 
of these grades. While questions of hybridity can be settled 
only experimentally, there seems to me to be no other way of 
accounting for conditions in this group than by assuming free 
hybridization. 
The species represented in the collection are Vaccinium 
corymbosum, atrococcum, angustifolium (pennsylvanicum), cana- 
dense, and vacillans. The last two are not common and did not 
present any particular diversity, although it is not impossible 
that cross pollination of corymbosum and canadense is respon- 
sible for some of the variations observed. Vaccinium nigrum 
Britton may be a distinct species from the var. nigrum here dis- 
cussed, which latter appears to me to be a variety of V. penn- 
sylvanicum. 
It is worthy of note that all the forms discussed grow together 
indiscriminately. There is no particular habitat that is especially 
favorable to any of them. All grow taller in shaded locations 
or when massed or amidst other shrubbery, and more low and 
spreading when in open sunny positions. I have been surprised 
to find a plant a foot taller than myself that certainly appears 
to belong to V. pennsylvanicum, unless it be a hybrid of that with 
V. corymbosum, which is not at all improbable. 
V. corrmBostum L. The typical plant is tall, forming large 
clumps, with spreading branches and leaves, the latter more or 
less broad, the margin entire, the entire plant glabrous, the 
berry large and blue. Although the species, in other forms, is 
the predominant one of the locality, this typical form was not 
found. The nearest approach to it was an occasional plant 
differing only in slight hairiness on the veins of the lower leaf 
surface. 
Number 1 of my collection represents the form just mentioned, 
except that the leaf margin is sharply serrate with bristle- 
pointed teeth. The leaves are quite pale beneath, but are 
not glaucous. 
Number 2 differs from Number 1 in having the lower leaf sur- 
face very pubescent and the twigs slightly so. The hairs are 
