FRUITS AND SEEDS 



227 



If some pollen grains chance to adhere to the feathery 

 stigma, they develop a long tubular process by the protrusion 



Fig. 31.- Young Pistil of the barley. 



St, stamen ; /, ovary ; n, stigma with feathery branches ; I, the tissue tlirough whicli the 

 pollen tube gi-ows; 0, ovule ; /, the integuments ; m, raicropyle ; e, embryo sac. 



of the delicate inner coating (intine) through the thin portions 

 of the hard outer coat (extine). This pollen tube makes its 



