3:.2 



PLANT S'lTDIIW 



are dry ami powdcrjs and are scattered far and wide l)y the 

 wind. In tlie pines and their allies the pollen-grains are 

 winded (Fig. 300, i)), so that they are well organized for 

 wind (listrDjution. Tliis transfer of pollen is called ^jo/- 

 lunifiim, and those plants that nse the wind as an agent of 

 transfer are said to 1)0 anemopJiilDiis, or "wind-loving." 



The pollen must reach the ovule, and to insure this it 

 must fall like rain. To aid in catching tlie falling pollen 

 the scale-like carpels of the cone 

 spread a,pa,rt, the pollen -grains 

 slide down their sloping surfaces 

 and collect in a little drift a,t the 

 l)ottom of ea.ch carpel, where the 

 ovules are found (Fig. -310, .1, 11). 

 'IMie Haring lips of the microp3'lo 

 roll inward and outward as they 

 arc dry or moist, and hy this mo- 

 tion s(uno of the pollen-grains a.re 

 caught and pressed down upon the 

 aj)cx of the nucellus. 



In tliis position the pollen-tuhe 

 dcvclo])s, ci'<iwds its way among 

 the cells of tlie nucellus, reaches 

 t]i(5 wall of the eudiryo-sae, and 

 penetraling that, reaches the necks 

 of the archegonia. 



2.]-i. The embryo. — r>y the act of 

 fertilization, an oospore is formed 

 within the archcgoniuui. As it is on tlu*^ surface^ of its food 

 supply (the cndos])erm), it lirst develops a long cylindrical 

 jirocess (.■-•//.sy^v/.s-cr), which penetrates the endosperm and 

 develo])s the eml)ryo at its tip. Tu Ihis way the emliryo lies 

 indieddcd in the midst of its food supply (I'^ig. :ll.')). 



231!. The seed. — While the emhryo is develoiiing, S(uue 

 important changes a.re taking ]il;icc in tlic ovule outside of 

 the emlospcrnt. 'I'lii^ most, noteworthy is tlic eluingc which 



Pio. 31.S. Emliryos of jiinc : .1. 

 ver}' yonng cniljiwos l/.ve at the 

 tips of ]inv^ !iii(] coiitortcfl siis- 

 licnsors l.vi ; fl. nidcr ciiiljiwo, 

 showiriL.' attachinriit ti. snspiai- 

 son.il, llii'cxIrnsivrr.Hitslii'alli 

 («■//), l-ont lip Kr.M, slciii ti|> 

 (n, and (aityl. 'lions in.-AfliT 

 STKAsnuiUiKi:, 



