20 BOTANICAL GAZETTE [JANUARY 
have a pollen chamber in the nucellus in which the pollen grains 
lodged; no pollen tubes are known and the indications are that 
they were not developed; (2) in Cycadales the pollen lodges in 
an already prepared pollen chamber in the nucellus and forms 
haustorial branching pollen tubes, which do not penetrate toward 
the female gametophyte and take no part in transferring the 
ciliated sperms to the archegonia; they are haustorial and nutritive 
in function; the way for the sperms is cleared by the gradual dis- 
solution of the cells forming the bottom of the pollen chamber; 
(3) in most of the Coniferales the pollen passes down to the 
tip of the nucellus, where it puts out a pollen tube that is 
both nutritive and a sperm carrier; (4) the Araucarineae, and to 
a less extent Saxegothaea, are pollinated on the ovuliferous scale 
at a distance from the ovule, from which point a pollen tube grows 
toward the micropylar end of the ovule and there enters the pro- 
truding nucellus. 
Another fact that seems to me especially significant in any 
attempt to account for the origin of these various habits is that in 
Araucaria, some podocarps (13) related to them probably, and 
in cycads, the embryo is not mature when the seeds are shed and 
keeps on growing after the seeds fall. It appears to me that this is 
the sort of habit one would theoretically expect to find in primitive 
seeds for reasons stated below. It adds strength to this supposition 
that Cycadales are universally recognized to be primitive plants, 
and that many investigators believe the araucarians to be the 
modern representatives, little changed in many ways, of a very 
ancient line and to be closely connected with the podocarps. 
Perhaps it will be worth while to attempt a brief analysis of the 
possible origins of the four classes of pollination devices mentioned 
above. 
CYCADOFILICALES.—Whether the Cycadofilicales are more 
primitive than the Cordaitales is a debatable question, but that 
they exhibit their seeds on less modified foliar organs affords some 
reason for thinking that the seeds themselves are also less modified. 
Physostoma elegans (17) will serve as a starting-point in an attempt 
to work back to the origin of seeds of this type. In the seeds of 
this type the integument is split up into more or less divergent lobes 
