92 
Agnes Robertson. 
THE TAX0IDEA2; A Phylogenetic Study. 
By Agnes Robertson, D.Sc. 
Quain Student in Botany ; University College, London. 
[With Plate I.] 
I.—Introduction. 
ARLY in 1904, at the suggestion of Professor F. W. Oliver, I 
began to make a study of the Taxoideas. At that time the 
the minute structure and development of the reproductive organs 
of the group were not known with any completeness except in 
Taxus, but in the course of the last three years several papers have 
appeared on the subject, culminating quite recently in Professor 
A. A. Lawson’s interesting study of Cephalotaxus, (see Literature 
Citations, 16, 17, 18, 19, 26). We are now acquainted with at least 
the main outlines of the reproductive processes of these plants, and 
a considerable mass of information has accumulated as to their 
floral morphology, anatomy, etc., so that it seems as if the moment 
has come to enquire what bearing this knowledge may have upon 
our ideas as to the phylogeny of the group. I have made some 
attempt to do this in the following pages. I should like to take 
this opportunity of thanking Professor F. W. Oliver for the help 
and encouragement which he has constantly given me in the study 
of the group. Before entering on any general discussion I have a 
correction to make and a few observations to record. 
11.—Observations. 
(a). Torreya californica. Torr. 
1 wish to begin these notes by correcting an error into which 
I fell in a paper on Torreya californica (17) published in this journal 
in 1904. I stated there that the division of the “ body cell ” nucleus 
of the pollen tube gave rise to two sperm nuclei of equal size. 
Since my paper was published an account of Torreya taxifolia by 
Coulter and Land (19) has appeared, in which the division of the 
body cell in this species is described as unequal, thus resembling 
that of Taxus, in which the functional male nucleus is greatly 
larger than the functionless one. The discrepancy on this point 
between my results and those of Coulter and Land, made me re¬ 
examine my preparations, and I have come to the conclusion that 
my statement of 1904 was incorrect. Pollen tubes were compara¬ 
tively scarce in my material, and I chiefly based my statement on 
