322 



Belling. 



could usually be distinguished, or had only a minute cavity to represent 

 the embryo -sac (Fig. 15). The perfect embryo -sacs measured about 

 330 — 420 by 100—140 microns, ^\^th well-formed egg-cell, synergidae, 

 and polar nuclei. The cavities of aborted 

 embryo-sacs or megaspores measured about 

 10—50 by 10—40 microns. (B. F. Floyd 

 again examined my preparations, and verified 

 my observations as to the numbers of normal 

 and aborted embryo-sacs.) Thus it is certain 

 that 50 per cent of the embryo-sacs abort 

 in the buds. (These flowers were picked in 

 the height of the flowering period, the ova- 

 ries cut open at tiie base, fixed \\ith Carnoy's 

 fluid for 12 hours, embedded in paraffin 

 through xylol, cut into longitudinal sections 

 14 microns thick, and stained with iron-alum 

 haematoxyUn and Orange G in clove oil.) 

 The distribution of the perfect embryo- 

 sacs (E), and the aborted embryo-sacs (0), in 

 the 18 ovaries, is as follows (see also Fig. 16, 

 wliich is constructed from the serial sections). 



Fig. 15. Somewhat oblique section 

 of another sterile ovule from a 

 flower of the first generation of 

 the Velvet by China cross. Show- 

 ing a small cavity at the apex 

 of the nucellus. 



(1) E— E- 



(2) E — E- 



(3) E — E 



(4) E — 



(5) E — E- 



(6) — E- 



(7) E — 0- 



(8) E — E- 



(9) — 0- 



(10) E — 0- 



(11) E — 0- 



(12) E — 0- 



(13) E — 0- 



(14) () — E- 



(15) 0- E- 



(16) 0-E- 



(17) E-0- 



(18) 0-0- 



-E — E — 



-E — E — — 



— — E 



— — E 

 -E — — — 

 - — E — E 

 ■ E — — — E 



E — E — — 

 ■0 — 0—0 



0— E— E— E 



0— 0— E— E 



E — — 



0-0 — E 



E— E— E— 



E— 0— 0— 



E — — - E 



E — — E 



O — — E 



