The Taxoideae. 
95 
The relation of Cephalotaxus, Torreyn, and Taxus to the other 
Conifers has been the subject of much controversy. According to 
our present imperfect knowledge of the geological history of the 
Coniferales, the Taxaceae appear at a somewhat later period than 
the Abietine^e ; more complete information however is needed before 
we can draw trustworthy deductions as to the history of the group. 
There are two contrasting views as to the position of 
the Taxoideae:— 
1. That the Taxoidece are a group retaining relatively primitive 
characters (Strasburger, 5 ; Coulter and Chamberlain 9 ; Worsdell, 
10, etc.) Those who take this view commonly regard the Taxoideae 
as descended from some group of the Fern-Cycad alliance. 
2. That the Taxoidece are relatively specialised, while it is 
rather the Abietineae which should be regarded as a primitive group. 
(Jeffrey, 20; Thomson, 21 ; Lawson, 26.) 
We will begin by considering the evidence for the first view. 
The anatomy of the three genera offers some distinctly primitive 
features. More traces of centripetal xylem are found here than in 
any other family of Conifers. (For references on this point see 
Robertson 22, p. 263). Strasburger (5) has shewn that Taxus has 
no albuminoid elements in its secondary phloem rays, that is to say 
the secondary structure of the phloem is not more specialised than 
the primary structure. This character, which is shared by Ginkgo 
and Araucaria, he regards as an indication of primitiveness, 
contrasting with the specialised anatomy of the Abietineae, in which 
the albuminoid cells of the secondary phloem are confined to the 
rays. Strasburger looks upon this anatomical evidence as a con¬ 
firmation of his view that any explanation of the floral structure 
of the Coniferae must start from the Taxads. 
The large erect seeds of the Taxoideae recall those of Cycas 
and Ginkgo in their macroscopic characters. Professor F. W. 
Oliver (14) who has worked out the structure in the case of Torreya 
and has compared it with palaeozoic seeds, describes the vascular 
anatomy as peculiar and isolated among recent plants, and regards 
the seed as of a distinctly archaic type. 
The stamens of the Taxoideae, like those of Araucaria, are 
characterised by possessing more than two pollen sacs. This is 
probably a relatively primitive character, representing in a very 
general sense a stage between numerous pollen sacs, such as we 
find for instance in the Cycadales, and the definitely bisporangiate 
condition met with in such a Conifer as Pinns. But it is necessary 
