INTRODUCTION. II 
and 15th, and in the White Mountains, two weeks later still; 
that is, in low or moderately elevated land. Between Portland, 
Maine, and Moosehead Lake, there is thought to be a differ- 
ence of at least two weeks in plants that bloom in spring; 
“this difference lessening as the hot weather comes on.” The 
amateur collector will find that it makes a good deal of differ- 
ence in point of time, whether his search is made on the north 
or south side of an elevation; whether in shaded or open 
ground; and, moreover, will often discover that the county 
map on which he has relied is of little use in locating 
“stations,” for he can never be sure that the plants he has seen 
in one swamp will occur in a corresponding swamp in the 
next township; and, indeed, it is highly probable that 
species abundant on one side of a mountain range will en- 
tirely disappear when he reaches the other side. In the case 
of Eastern Massachusetts, to give a clearer illustration, cer- 
tain Orchids grow within thirty miles of Boston, but one’s 
success in getting them depends chiefly on whether he meas- 
ures the thirty miles north or south of the city. The subtle 
influences of soil and climate sometimes contradict one’s 
learned conjectures very unpleasantly. 
I am indebted to Professor Gray for permission to make 
liberal extracts from his Manual, to Rev. Henry P. Nichols 
of New Haven, Conn., Dr. N. L. Britton of Columbia Col- 
lege, and especially to my friends Henry H. Donaldson and 
Frederick H. Horsford, to whom this work is informally dedi- 
cated. 
ORCHIS FAMILY IN NEW ENGLAND. 
(Synopsis from, and mainly as arranged in Gray's Manual.) 
I. Anther only one. (The 2 cells should not be mistaken 
for anthers !) 
TRIBE I. OPHRYDEA. Anther (of 2 separate cells) borne 
