144 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9, 
comparable forms. Because of this extremely complex material, the present 
paper will deal mainly with what are believed to be representative types of 
regressive reversions. 
Genealogical chart of progressive sports of bostoniensis 
Black face type indicates division sports. Italics indicate sports showing ruffling. 
Plain Roman type indicates dwarfing. Small capitals indicate other types of variation. 
Whitmani 
"improved" 
Whitmani 
compacta 
Piersoni . 
Barrowsi Whitmani . 
SPLENDIDA 
superbissima. .muscosa 
elegantissima . elegantissima 
"improved" 
elegantissima sport like 
compacta .... Whitmani 
compacta 
Piersoni 
"improved" 
Elmsfordi 
magnifica 
gracillima 
Goodi 
? Smithi Craigi 
superior 
Anna Foster 
Harrisi Wm. K. Harris 
EXALTAT A. bostoniensis i Roosevelti 
Sport like 
Wm. K. Har- 
Teddy Jr. 
falcata 
f Dwarf sport . . 
\ Randolphi 
[ Smallest dwarf 
?? Amerpohli 
Fish-tail 
sport 
Scotti \ Wagneri 
Scholzeli Three-pinnate 
sport 
f New Jersey 
Giatrasi . . . . \ 
{ Queen Sophie 
Gretnai 
Since the progressive varieties all originated from one form, bostoniensis, 
it will be interesting to consider first the primary vSports of that fern. To 
what extent has the original process been reversed? After that, the rever- 
sion of the different grades of the division series will be considered. What 
are the products of the reversion of twice pinnate forms, of thrice pinnate 
forms, etc., etc.? Are the progressive steps each retraced in reversion? 
Can a four-times-pinnate variety produce thrice, twice, and once pinnate 
reversions, or only one of these? Similar questions suggest themselves in 
