10 AMERICAN FERN JOURNAL 
ties for closer study and experiment. This collection 
now numbers over seventy different varieties, named and 
unnamed, and I have ordered for delivery in the near 
future all European forms catalogued, besides commis- 
sioning collectors in the tropics to send me wild forms. 
The varieties of N. exaltata bostoniensis may be roughly 
classified under three heads: (1) variations which show 
increase in the amount of division; (2) variations show- 
ing increase in the undulation of the pinnae; (3) varia- 
tions showing various degrees of dwarfing. Besides 
these, the forking of pinnae and leaf tips, the “fish-tail” 
variation, as the florist calls it, is also rather common. 
Perhaps the most interesting fact about these variations 
is that they are nearly all progressive or orthogenetic; 
i. e., each new form along any given line seems to carry 
the potentiality of producing another sport showing 
the same new character in greater development. This 
is well illustrated in the series shown in Plate 1. 
The forms represented in Plate 1 illustrate progressive 
variation along the line of increased division of the leaf. 
The relationships can be well indicated by setting down — 
the technical scientific names of the different varieties 
pictured with the figure numbers and amount of division. 
Fig Name Amount of division 
1. N, exaltata bostonieusis.................. ...... 1—pinnate 
2. N. exaltata bostoniensis Piersoni................... 2-pinnate 
3. N. exaltata bostoniensis Piersoni Wiitmani, 2.2 3 2.. 2-3—pinnate 
4. N. exaltata bostoniensis Piersoni Whitmani gracillima 3-pinnate 
5. N i 
- exalt. bost. Piers. (Whitmani?) Smithi Craigi.. . , 5-pinnate 
It should be noted that the varieties Piersoni and Whit- 
mani were really separated in origin by another form, 
Barrowsi, which was not available when the illustra- 
tion was made. The complete history of the origin of 
the 5-pinnate form, Craigi, is uncertain. It may have 
come through another sport than Whitmani but this 
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