514 r BOTANICAL GAZETTE [june 



structures. Strasburger (35) described the bundle supply to 

 the three pairs of decussate scales and to the ovule, accepting 

 Van Tieghem's interpretation of the situation. Later he reversed 



terminal 



bundles 



position of the ovule. He 



as consisting of long, thin- walled elements, but containing no 



tracheids. Miss 



from 



from cases in which the united bundle 



from 



from 



of the bract of the last pair." Miss Aase also pointed out the con- 

 centric character of the bundles in the base of the ovule, and the 

 possible ending of one of the bundles before reaching the ovule. 

 From her study the suggestion is made that there may have been 

 a fusion of sporophylls to form a single structure, implying "the 

 reduction of the ovules to one, the complete fusion of two sporo- 

 phylls to the integument of the ovule, and finally the reduction 



sm 



in the wing of the ovule." She concludes 



necessary." 



materia 



from those of T. baccata, and a brief statemt.it of the situation will 

 be sufficient. The secondary axis receives two large bundles from 

 the cylinder of the primary shoot (figs. 21, 44), these uniting at 

 their edges and forming a closed cylinder (fig. 45). The traces 

 to the first pair of scales are given off near this level (fig. 46). 

 Traces are then given off to the second pair of scales (fig. 47), above 

 which the gaps formed by the first pair of traces are closed, giving 

 again two large bundles in the cylinder (fig. 48). The bundles to 

 the third pair of scales are given off directly above those to the 

 first pair (fig. 40), these bundles being usually quite short, at times 

 not even reaching to the scale, but ending in the cortex itself. The 

 main cylinder now consists of four bundles, two on each side, the 

 pairs being separated by the gaps formed by the third pair of scale 

 bundles. The two bundles of each pair turn through an angle of 

 45 and unite laterally (fig. 51), closing the gap formed by the second 





