PLAiXT LIFE. 



few or many bosses, points, or ridges, as in other spores 

 (A-D, fig. 271). In the pines the outer layer of the wall 



G'g-^s 



Kig 1*67. Fig. 269. 



Fig. 267. — Corolla of Alcanna tinctoria slit and laid open, showing almost sessile 

 stamens united with corolla above the middle of tube, s, scale-like outgrowth from 

 corolla. The tube between .v and the notches at edge of corolla result from the growth 

 of a ring of tissue beneath the five fundaments of the corolla which produce the five 

 corolla lobes c. Having grown so tar, a ring of tissue inside, on which the stamen fun- 

 daments were developing, became involved in this upward growth, and thus the sta- 

 mens were carried up and arise just above j. Magnified 4 diam. — After Berg and 

 Schmidt. 



Fig. 268. -Very young flower of Hypericum perforatum, seen from above, showing 

 s, sepals; /•, fundaments of petals ; a, a, a, fundaments of the three stamens, each al- 

 ready with two lateral growing points, the fundaments of branches, appearing; g; fun- 

 daments of 3 carpels. Compare with figs. 269 and 270. Magnified about 50 diam. — 

 After Frank. 



Fig. 269, An older stage of fig, 268, showing only the fundaments of stamens, a, and 

 of carpc-K. g: < in the- latter at the angles appear the fundaments of the three styles. 

 Many branches of a have begun. Compare tig. 270. Magnified about 50 diam. 

 — After Frank. 



forms two bladdery swellings which make the spore relatively 

 lighter (E, fig. 271). The pollen spores arise in the spo- 

 rangia in fours in each mother cell, as described in ^j 306. 

 (See also fig. 264.) They are either dry and powdery when 



