290 
N. Bancroft. 
Heterosporous Pilicales. 1 Fritsch (23) considers Monocotyledons 
and Dicotyledons to be two independent groups having evolved from 
a common ancestor, extinct and unknown, by way of the Helobieae 
and Ranales respectively, or having had separate origins in extinct 
Gymnosperms or Pteridophyta. Lindinger (40; see also 39), in 1910, 
has been one of the most recent exponents of the “ independence 
theory.” From a consideration of root and stem-structure in 
Monocotyledons, he concludes that this line is independent so far 
Q Lj m noap c.rmac 
DicoTcjledones 
MonocoTyledones 
Chori facta lae 
Syrnfaetalac 
Monochlamydeae 
Dialyfadbleae 
X/ephallpTae 
Mupicales 
1 (Judlandales 
AUpticales 
1 wPoly^onales 
Cenfpo 
1 ^-^Hamarr 
Tpicooca 
,r Ppoteales 
^bantalales 
! fbalicales 
( RJoePales 
sfaepmae- =► 
didales 
► R>lycapfaicae _ 
(/Rhoea dales 
faPapieTales 
\9uttije pales — 
/Rosales - 
* My pTales 
i 
-> Columnifepae^ 
^Gpuinales l 
TePebinThalesj 
IfaCelasTpales 
fat Rhamn ales 
^ UmVoellijlopae 
Plumba£ir\ales 
^Stjnandpae 
1 bicopnes 
VF^imulales 
_Jub'flopae 
■1* Conlo pTae 
f Diostay pales 
"\Corvdvulales 
— >lj2tusTpales 
-^Rutaialec 
>(Helo\oiae 
ItfLiliiflopqe 
•i^Enanhoblostoe 
jWMlumijloPoe 
vfaCy joepale s 
V'^aciTarntneae 
Xfiunandr»ae 
SbadicifloPae 
Diagram III. 
The Evolution of the Monocotyledons, according to Wettstein’s System 
(1911). 
as the Dicotyledons are concerned; nor can any connection be 
traced with known Gymnospermous types, recent or fossil. In 
considering the characters of the primitive Monocotyledon, Lindinger 
mentions Dracaena, Aloe and Yucca as having retained ancestral 
characters in the purest form—an interesting point in connection 
1 They admit, however, that “ the arguments in favour of the mono- 
phyletic origin of Angiosperms are strong; and if this view be accepted, the 
derivation of Monocotyledons from primitive Dicotyledons seems to rest on 
stronger evidence than the reverse relationship” (p. 288). 
