i 9 2o] DUPLER—TAXUS CANADENSIS 503 



all conifers as a pistil. Trew's observations, in 1767, that the 

 ovule of conifers receives the pollen directly, the representation 

 of Trew's observations by Targioni-Tozetti in 18 10 (Radais 24), 

 and Brown's (6) announcement of gymnospermy introduced a 

 fertile topic for debate. For a time these newer views met strong 

 opposition, Richard (25), for instance, declaring that there are 

 no plants with naked ovules or without an ovary, and holding that 

 the ovular integument was the perianth and the nucellus the pistil 

 of the flower. Baillon (2) was also a vigorous opponent, holding 

 the ovule to be a 2-carpel ovary with a single orthotropous ovule. 

 Parlatore (22), Sperk (34), with others, and even Strasburger 

 (35) f° r a time also held to the ovarian theory of the ovule. 

 Another group, among whom were Schleiden (29), A. Braun (5), 

 Sachs (26), and others, accepted Brown's view as to gymnospermy. 

 Strasburger later accepted the same interpretation, and the 

 question of the gymnospermy of Taxus has been generally accepted. 

 The morphological position of the ovule has not been so 

 definitely settled, and it may yet be regarded as an open question 

 whether it is a lateral structure, foliar in origin and only secondarily 

 terminal, or a true terminal structure, unrelated to the scales in 

 its origin. The first of these views depends upon the assumption 

 that the ovule in gymnosperms must always be related to sporo- 

 phylls, present or suppressed; the second that the ovule may arise 

 from the axis itself, independent of lateral organs. Among the 

 early workers Schleiden (30), Schacht (28), and others regarded 

 the ovule as terminal to the branch. On the other hand, Don (ii), 

 Caspary (7), and others held to the foliar origin of the ovule. 

 Van Tieghem (37), using the anatomical method as a basis of 

 interpretation, concluded from the orientation of the bundles that 

 the ovule represents the first and only leaf of a shoot of the third 

 order in the axil of the sixth bract of the secondary shoot, a view 

 also accepted by Strasburger (35). Sachs (26) regarded the 

 ovule as secondarily terminal, the bract nearest the ovule playing 

 the role of the carpel, but later (24) changed his opinion, admitting 

 the ovule to be terminal and a modified stem. Strasburger also 

 abandoned his earlier position and held that the ovule is strictly 

 terminal on the axis tip, that no relation to the last pair of scales 



