292 PHYLUM XIV. ANTHOPHYTA 



(c) Make a similar macroscopic examination of the leaves (of 

 the sporophytes), noting whether they arise singly at the nodes 

 ("alternate" leaves), or in pairs ("opposite"), or in whorls of 

 three or more ("whorled"); determine the shape (sometimes 

 variable), margin, surface, size and variation of the leaf blades; 

 the length and shape of the petioles; and the shape and position 

 of the stipules (where present) . For the microscopic anatomy 

 make cross-sections of the leaves and note shape and size of 

 the epidermal cells, thickness of cuticle, character of hairs, 

 type and location of vascular bundles (veins), and amount and 

 location of the forms of parenchyma tissue (the mesophyll) 

 called "palisade" and "sponge" parenchyma respectively. 

 In cross-sections of the petioles note size of intercellular spaces. 

 Make sections of the blade parallel to the surface, and note the 

 comparative frequency of the stomata in the upper and lower 

 epidermis, shape of epidermal cells (and correlation with type 

 of venation if any), component tissues of the veins and the 

 course of the latter, etc. 



(d) Study the macroscopic structure of the flowers observing 

 them from above, note that they are radially symmetrical (ac- 

 tinomorphic). Note the shape of the axis (torus) and how the 

 flower parts are attached to it, making a longitudinal section if 

 necessary; observe that it does not surround or grow fast to 

 any floral parts. Note the number and arrangement (in spirals 

 or whorls) of the megasporophylls (carpels), and observe that 

 they are free from one another (apocarpous) ; distinguish the 

 ovary and stigma (and style if present) ; make transverse and 

 longitudinal sections of carpels and observe number and loca- 

 tion of the megasporangia (ovules). Count and note arrange- 

 ment (in spirals or whorls) of the microsporophyUs (stamens) ; 

 examine one carefully and note the filament (stalk) and anther 

 (cluster of microsporangia); section transversely an unopened 

 anther and note the four microsporangia; examine the mi- 

 crospores (pollen) from a mature anther. For the petals note 

 number, shape, color, size, and particularly their arrangement 

 (spirals or whorls). Make a similar study of the sepals; note 

 whether free or united; observe their arrangement with refer- 

 ence to the petals. 



(e) The study of the female gametophyte wiU require the 

 use of prepared slides. If possible they should show the devel- 

 opment from the megaspore mother-cell (arohespore) to four 



