PLA.TE 19 



lyongitudinal section of the pistillate spikelet of corn at the time the silk is ready 

 for pollination: r, rachilla; g, lower empty glume; %' , upper empty glume; 1, lemma 

 or flowering glume of the fertile flower; V, lemma or flowering glume of the sterile 

 flower; pa, palet of the fertile flower; pa'', palet of the sterile flower; sf, sterile flower; 

 st, rudimentary stamen of the fertile flower; ova, ovary of the pistil; co, cavity of the 

 ovary; sk, silk or style; sc, stylar canal; vbs, one of the fibro- vascular bundles of the 

 silk. 



Through the sheath cells that siuround the bundle the pollen tube travels down the 

 silk; vsc, sheathlike cells through which the pollen tube travels from the vascular 

 bundle to the cavity of the ovary; vb, fibro- vascular bundles that supply the parts 

 of the spikelet; ov, ovule; ovc, ovule coats; mic, micropyle; es, embryo sac. X 45- 



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