black: inflorescence and fruit of pyrus malus 531 



space directly over the remaining part of the apex of the axis. 

 The fact that the vegetative point of the flower-axis is not entirely 

 used up is observed and figured by Goebel (22) who places some 

 of the flowers of the Pomaceae in a "transitional position between 

 the perigynous to hypogynous."^ He states that "the five carpels 

 appear as papillae upon the hollowed-out inner surface. They 

 take up the whole inner margin of the cavity, but at the base 

 there is visible, and even at later stages it is so, the flattened 

 vegetative point of the flower." It will be observed in plate 36, 

 figure I, that the unused portion of the axis has become slightly 

 elevated so that the apex is above the base of the ovarian cavities. 

 This elevation is caused by a slight growth of the apex of the 

 axis after producing the last circle of floral members, i. e., the 

 pistils. Cell division was frequently observed in this region. 

 In a median longitudinal section the unused apex of the axis 

 presents a flattened appearance. Around this flattened area the 

 inner surfaces of the carpels arise somewhat gradually. The 

 section shown in plate 36, figure i, or plate 38, figure 2, is 

 not a median section and the slight notch in the center is due to 

 the ovarian groove of the adjacent carpel. A flower is shown 

 just before expanding in plate 36, figure 2. The sepals and 

 petals arch over the stamens and pistils. The pollen is mature in 

 the anthers. The styles have elongated and carry up with them 

 the groove to the stigma. The papillose stigmatic surface is 

 apparent before the flower opens. A young ovule is shown in the 

 ovary of one pistil. The continued growth of the torus elevates 

 the sepals, petals, and stamens so that they are above the ovaries. 

 The ovaries thus become epigynous. 



One ovule develops upon each placenta of the ovary, thus two 

 ovules are usually found within an ovary. ■ Early stages in the 

 development of the ovule are seen in plate 36, figures i and 2, 

 and PLATE 38, figures i, 2, 3, and 5. Figure i, plate 38, shows 

 a very slight elevation upon the placenta. This rounded pro- 

 tuberance increases in size as shown in the next figure (figure 2). 

 Here the section is so cut that two similar ovules are seen in 

 different ovaries. Below the ovule a very slight projection, the 

 obturator is observed, similar to that shown by Pechoutre (23) for 

 the pear (figure 3, plate 38). This elevation does not appear 



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