46 SUMMARY. [CHAP. 



Between the outer glumes and the lowest flowering-glume 

 of the spikelet in some grasses, and, in others, above the 

 uppermost perfect flower of the spikelet, there are one or 

 more empty glumes, which are called, by some botanists, 

 sterile flowers. Occasionally a staminate flower is borne 

 in the axil of the glume next below or above the perfect 

 flower. Wheat may be thus described : Spikelets with 

 two outer glumes ; flowers with omtfloivering-glume, one 

 pale, two lodicules; stamens triandroiis, hypogynousj 

 pistil syncarpous, ovary superior. 



6. Let us now proceed to review, as before, the five 

 plants last examined, viz. Arum, Orchis, Daffodil, Tulip, 

 and Wheat. 



They all happen to be herbaceous plants. The leaves, 

 excepting in Arum, do not present the obvious distinction 

 of petiole and blade, and, with the 

 same exception, the veins of the leaves 

 are parallel and not irregularly netted. 

 Those which have the essential organs 

 of the flower enclosed in a perianth 

 have the leaves which compose it 

 arranged in two whorls (calyx and 

 corolla) of three each. We find the 

 five plants marked by (i) no obvious 

 distinction between blade and petiole ; 

 Fl n G al 3 tdon nS of Udl a (2) parallel-veined leaves ; and (3) the 

 grain of wheat, parts of the flowers in threes ; and, 

 SoT^S as in Dicotyledons, all of them have 

 basefof^he seed. their ovules enclosed in a pistil upon 

 the stigma of which the pollen is shed. 



7. We must now soak a few grains of Wheat for com- 

 parison with the seeds of Dicotyledons. We must, how- 

 ever, be careful not to regard the grain of Wheat as a 

 seed corresponding to that of the Pea or Bean, for it is a 

 Iruit, consisting of pericarp (ovary) and seed ; the pericarp 

 being closely adherent to the true seed. In the Tulip, 

 Daffodil, and other plants just examined, the seeds are 

 free from the pericarp, as is usual in flowering plants ; the 

 adhesion, in this case, may be regarded as accidental, 

 though it is very characteristic of the fruit of grasses. 

 Cutting the grain open, we find the embryo near the 

 base, occupying about one-fourth or one-fifth of its 



