39° APPENDIX. 



6. The sheathing base, in upper leaves branched to form two 

 stipules. 



7. Examine and compare the various forms of leaves: {a) the 

 lowest, having sheathing bases without petiole or blade, passing 

 gradually into (b) the best developed foliage leaves; (c) these near 

 the flowers losing petiole and diminishing blade, becoming bracts; 

 (d) the yellow perianth leaves ; (<r) next within these the yel- 

 lowish stamens (micro-sporophylls); (/) the flattened pod-like 

 green carpels (mega-sporophylls) each forming a simple pistil. 

 (11 160, 161.) 



8. Bisect a flower lengthwise. Observe the three sorts of 

 leaves, perianth, stamens, and carpels; their relation to each 

 other and their insertion separately on the enlarged stem, the 

 torus. Separate some from an old flower and note the scars left 

 by their fall. (1 330.) 



9. Are perianth leaves similar, or of two sorts? (1 354.) 



10. Dissect off a stamen. Observe the two parts: (a) the slender 

 stalk, filament, and (b) the enlarged part, anther. Note in the 

 anther the two lobes, each with a shallow groove marking the 

 position of the two pairs of sporangia. Tear open the sporangia 

 with a needle and observe the innumerable microspores (pollen 

 grains) which they contain. Examine a naturally bursted anther 

 and determine how they open. (HI 345-348.) 



11. Demonstration. Cut a thin section of an anther from a bud 

 and show (a) the four sporangia, in pairs, entirely distinct, and 

 the point at which they become confluent as they burst; (b) the 

 pollen grains. (1 351.) 



Dissect off and examine a pistil. (1 33S.) Observe 



12. At the apex the roughened area, the stigma (1 336), sessile 

 (1 337) upon 



13. The enlarged part, the ovulary (I335). Observe its flat- 

 tened form and the groove along one edge. Split it along this 

 line, flatten it out carefully and note the ovules attached to the 

 edges. (1 343.) 



14. Cut several transverse sections of the pistil and observe the 

 thickened edges of the carpel, forming the placenta, to which 

 ovules are attached. Compare sections. Are all ovules attached 

 to same edge ? 



15. Demonstration. Prepare a longitudinal section of an ovule 

 of a lily and show the two integuments; the sporangium, enclos- 

 ing the single megaspore, or embryo sac. (H 340, 394.) 



