28 BOTANICAL GAZETTE [JANUARY 
scale. If such evidence should be forthcoming, the line of argu- 
ment that has been‘used in connection with the lycopod seeds could 
be equally applied to the Cordaitales. The cordaitean seeds were 
formed in cones, and I should strongly expect that some of them 
were pollinated on the scale instead of the nucellus. 
The theory would run something like this. When the seed 
habit was developed, the plants were in the midst of acquiring the 
cone habit. Pollination would therefore differ in nearly related 
plants. The ones that first perfected the pollination habit would 
be likely from the first to be pollinated on the nucellus. The ones 
forming cones first probably acquired thereby the habit of pollinat- 
ing the scale. Some of these may have deposited the pollen so 
near the nucellus that they soon passed through the intervening 
stages.and so show no special differences from those that always 
had had the pollen on the nucellus. The history of the pollen 
chamber would be the same as that already outlined for the Cycado- 
filicales. Whether these ancient plants that gave rise to modern 
conifers were more like araucarians or other modern conifers in 
other respects cannot, of course, be decided on these grounds. It 
does seem to me that the mesozoic conifers very probably did 
resemble the araucarians in respect to the seed and pollination 
habit. This might be equally true whether they resembled the 
araucarians in their vegetative structures or were more like the 
Abietineae, as has been vigorously maintained in recent years by 
some anatomists (10). nee 
The theory of the pollen tube above outlined is applicable to the 
structure of the male gametophyte itself. There is nothing to be 
explained away, as must be done if we attempt to derive the 
araucarian type from the pine type (11). The numerous pro- 
thallial cells are not then to be thought of as something to be 
explained away, but as what is left of the ancient prothallus. 
A figure (2, fig. 2) from Miss BENson’s paper on Lagenostoma 
seems to me to be capable of another interpretation than the one 
given by the author. The figure shows a number of pollen grains 
in the pollen chamber. At the upper right of the figure is a group 
of one large and several small cells. The large cell is labeled 
“a sperm,” and the smaller ones are said to be probably fungal 
