1899] Plants introduced by Minot Pratt at Concord, Mass. 169 
disappears altogether. The third case, although the one usually de- 
sired, is, alas, rarely attained, namely an adjustment of the flora by 
which the new element takes what may be styled a normal place in the 
vegetation, the planted individuals not only holding their own, but 
propagating themselves so that the species becomes diffused over a 
more or less considerable area without any such inordinate multiplica- 
tion as would displace an appreciable part of the native flora. 
The chance of obtaining this unusual result is so slight that such 
experiments are looked upon by botanists, in general, with suspicion if 
not disapproval. The matter is primarily one of horticulture rather 
than of botany, and to the botanist the problem of what can be made 
to grow in a given region is never of so much interest as the question 
what has, in the long struggle for existence, succeeded in growing 
there of itself. 
However, the efforts of the late Minot Pratt to enrich the flora of 
Concord, were conducted with so much care, skill, and patience, ex- 
tending over a long period of years and concerning a considerable 
variety of plants, that their results have a high degree of interest for 
the local botanist. 
It was Mr. Pratt's custom to obtain several or, if possible, many 
thrifty individuals of a species not indigenous about Concord, but ap- 
parently suited to its climate. These he would set out at various 
points about Concord, in conditions of soil, moisture, and exposure 
which most nearly approximated those of their original occurrence. 
The species chosen were mostly those of the northern states from Ver- 
mont to Illinois, and were usually selected for their attractive flowers, 
such as Claytonia, Sabbatia, Dodecatheon, or for their interesting or 
economic qualities, such as Camptosorus, Aralia quinquefolia, etc. 
These efforts extended over many years from perhaps 1860 to 1875, 
and the plants were frequently visited and carefully tended while get- 
ting a start. For some twenty years, however, they have been practi- 
cally left to themselves. Fortunately Mr. Pratt kept a record of most 
if not all of these introductions, the manuscript being in the Concord 
library. 
The treatment of these species in local floras has naturally pre- 
sented a somewhat awkward problem. It is known that many of them 
have occurred and some still persist in a practically “ wild ” state, so 
much so, in fact, that collectors who have come upon them, have 
sometimes insisted that they were *truly indigenous." Nearly all are 
