iqiq] DUPLER—TAXUS 357 



vascular bundle, when present, and occasionally by sclerenchy ma- 

 like cells along the outer margin of the midrib. In the young 

 strobilus the mesophyll of the scale is compact, but as the strobilus 

 matures large air spaces develop. In addition to the solitary stoma 

 found on the sporophyll, stomata occur on the strobilus axis between 

 the bases of the sporophyll s with rather surprising frequency, being 

 found only on this portion of the axis and not on the portion between 

 the upper scales and the lower sporophylls. While the functional 

 character of these stomata might be open to question, owing to their 

 position rather than to their structure, their chief interest probably 

 lies in their morphological significance as hereditary structures from 

 a more highly vegetative ancestral strobilus. 



During the autumn, winter, and early spring the strobilus has 

 the appearance of a globular "bud," the stamens being surrounded 

 by the uppermost scales (fig. 7). The axis between the upper scales 

 and the bases of the lower sporophylls is very short and remains so 

 until a few days before maturity, during the latter part of April in 

 central Pennsylvania, at which time there is a rapid enlargement 

 and elongation of this portion of the strobilus, the effect being to 

 push the sporophyll-bearing portion beyond the scales (fig. 9). A 

 similar elongation of this region is reported for Torreya calif ornica 

 (20). Coulter aiid Land described an enlarged pith region in the 

 axis of the strobilus in T. taxifolia, which the authors suggest may 

 be "an important storage region for the strobilus." No such 

 enlarged region was found in T. canadensis. In addition to the 

 elongation of this portion of the strobilus axis there is also an 

 elongation of the stalk of the sporophyll (cf. figs. 9 and 10), resulting 

 in the separation of the sporophylls from one another. 



The sporangia do not hang freely from the underside of the 

 disk, but are fused with the stalk on the inner side (fig. 9), and 

 laterally are separated from one another only by thin partitions, the 

 external furrows between the sporangia not extending all the way to 

 the center, the sporophyll and sporangia thus constituting a very 

 compact structure. Richard (19), Strasburger (22), and 

 Goebel (10) gave accounts of the dehiscence of the sporangium of 

 T. baccata, in which they pointed out the rupture of the sporangia 

 at the base and the umbrella-like movement of the epidermal wall. 



