2 q6 
W. T. Saxton, 
manner, but in tliis genus tlie pollen is deposited on the projecting 
tip of the nucellus, and not on the scale; thus Saxegothcea forms a 
connecting link between the Araucarians and other Conifers in this 
respect. 
Development and structure of male gametophyte. This is 
undoubtedly one of the most important guides to the larger relation¬ 
ships. Neglecting minor variations, six main lines of development 
maybe distinguished, which are as follows:—(I) Two prothallial 
cells formed which persist and proliferate, forming eventually a 
considerable (but variable) number of free nuclei in the pollen tube; 
tube nucleus and stalk cell formed (as they are in all cases), and 
body cell divides to form two nearly equal male cells. Occurs in 
Agathis and Araucaria. (II) As I, but body cell nucleus divides 
very unequally forming one male cell and a much smaller second 
nucleus lying at its periphery, or sometimes the body cell divides to 
form two very unequal male cells. (The prothallial cells may persist 
without dividing in some cases, or one only may persist, as in 
Phyllocladus). Occurs in Podocarpus, and some other genera. 
(Ill) Two transient prothallial cells formed, then tube nucleus and 
stalk cell, as usual, and body cell finally divides to form two subequal 
male cells, or sometimes male nuclei in a common mass of protoplasm. 
Occurs in Pinus, and several other genera. (IV) No prothallial 
cells formed. Tube nucleus and stalk cell cut off as usual; body 
cell nucleus divides to form two very slightly unequal male nuclei, 
which lie free in the cytoplasm of the tube. Occurs in Sciadopitys. 
(V a). As IV, but body cell divides very unequally to form either 
two very unequal male cells ( Torreya ), or to form one male cell and 
a second small male nucleus, which lies at the periphery of the male 
cell ( Taxus ). (V b). As V a, but body cell nucleus forms two equal 
or nearly equal male nuclei, which are either associated with unequal 
masses of cytoplasm (thus forming unequal male cells) or are em¬ 
bedded in a common mass of cytoplasm. Occurs in Cephalolaxus. 
Female gametophyte. As regards numbers 7 and 8, the 
differences found are either more or less correlated with more 
important divergences in the position of archegonia, or appear 
unimportant, as shown by the fact that the method of cell formation 
is markedly different in the two species of Sequoia, which, on 
other grounds, appear to be very closely related. 
The position of archegoninm initials (number 9) would appear 
at first sight to be identical with that of mature archegonia, but in 
two respects this is not necessarily the case, i.e., (i) archegoninm 
initials may be deep-seated, but may grow through to the outside of 
