i 9 2o] DUPLER—TAXUS CANADENSIS 493 



more complete references being available in the accounts of 

 Strasburger (35), Radais (24), and Worsdell (39). 



The earlier work was based largely on external features, and 

 attempted to homologize the structures with those of the angi- 

 osperm flower. This attempt seemingly persisted much later with 

 Taxus than with most other conifers, the gymnospermy of Taxus 

 not being quite so soon recognized as in other forms. The bulk of 

 the literature deals with the more theoretical questions, the actual 

 descriptive work not being so extensive. The discussion of the 

 literature will be presented in the text of the paper, in connection 

 with the several topics, in this way avoiding repetition and pre- 

 senting each topic in more complete form. 



Ovuliferous bud 



As previously pointed out (13), three types of buds are formed 

 in the axils of the leaves of a current season's shoot, namely, vegeta- 

 tive, staminate, and ovuliferous. The differentiation of the last is 

 first recognized by the appearance of the rudiment of a secondary 

 axis in the axil of one of its uppermost scales (fig. 1), this rudiment 

 appearing early in July. The ovuliferous bud begins early in the 

 spring, as a conical rudiment in the axil of a young leaf, shortly 

 after the beginning of the growth of the vegetative shoot, forming 

 usually nearer the tip than the staminate buds. Strasburger 

 (36) found the first differentiation of the ovuliferous bud in 

 T. baccata to occur about August 1. The structure can be dis- 

 tinguished by external features with certainty only when the 

 ovule has reached such size as to protrude beyond the scales, 

 usually not until spring. Jager (15) says that the ovuliferous bud 

 of T. baccata is evident about February 1, being slightly yellowish, 

 and the vegetative bud being reddish brown; but this is hardly a 

 safe criterion, owing to color variations. 



Primary shoot 



General features. — The ovuliferous organ in Taxus consists 

 of two structures: the primary ovuliferous branch, or, as it is more 

 generally known, the primary shoot; and the secondary shoot 

 on which the ovule is borne. The primary shoot arises directly 



