312 GENETICS IN RELATION TO AGRICULTURE 
examples of like improvement. Unquestionably the amateur plant 
breeder can find no more fascinating or productive line of activity than 
that of selecting and working with some particular group of species from 
this standpoint. 
Origin of Varieties in the Boston Fern.—In 1915 Benedict reported 
that he had accumulated about 40 different forms of the Boston Fern, 
all of which had originated so far as is known from bud sports. The 
following statements regarding the source of these new varieties are 
based on Benedict’s account. The original Boston Fern arose as a bud 
mutation from the tropical species, Nephrolepis exaltata. It was first 
Fie. 128.—1. The original Boston fern, Nephrolepsis exaltata bostonicensis; 2, the first 
bud sport from the Boston, N. exaltata bostoniensis Piersoni; 3, the Pierson fern next pro- 
duced elegantissima; 4, N. compacta, a sport from elegantissima. (Courtesy Brooklyn Botanic 
Garden.) i 
recognized as different from exaltata by F. C. Becker of Boston, and 
in 1896 it was named N. exaltata var. bostoniensis. The typical form of 
the species and the first sport, bostoniensis, are large growing ferns with 
uni-pinnate leaves (lig. 128, 1). In the remarkable series of bud muta- 
tions that have been derived from bostondensis within two decades, the 
principal characters undergoing transformation are, first, form of pinna 
and hence form of frond; second, size of frond; third, form of frond con- 
sidered independently of pinna-form; fourth, color of foliage. 
The original sport from the Boston fern was bi-pinnate; 7.e., each 
pinna was subdivided into little pinne or pinnules (Fig. 128, 2). This 
form appeared about 1900 in the establishment of F. R. Pierson of 
Tarrytown on the Hudson, and was named Piersoni or Tarrytown fern. 
It did not produce satisfactory plants because only part of the fronds were 
bi-pinnate; the remainder resembled the original Boston variety. 
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