MONOCOTYLEDONS 295 
before the Dicotyledons, as a lower class, in spite of the 
fact that they appear to have originated from the latter. 
The Dicotyledons are an earlier class, but they have 
risen higher than the later derived Monocotyledons. 
CLASS MONOCOTYLEDONEAE. 
THE MOoONOCOTYLEDONS 
533. Cotyledon one; leaves on the stem alternate; 
- vascular bundles in the stem scattered (as seen in cross- 
section), in the leaf blades parallel (“‘parallel-veined’’) ; 
perianth whorls mostly ternate (in 3’s). 
534. There are seven or eight types (orders) of Mono- 
cotyledons. The lowest of these (Alismatales) is rep- 
resented by the Water Plantain, already described. 
The others are briefly as follows: 
535. Lilies (Liliales). In a Lily the carpels (mega- 
sporophylls) have been reduced to three, and these have 
grown together into a single pistil (‘‘com- 
pound pistil’’), in which each carpel 
retains its ovule-bearing cavity (i.e. the Fi 
pistil is ‘“3-celled”’). The stamens (mi- 
crosporophylis) are in two whorls of @ 
three each: the petals are three; andthe =, 17 _—titium 
sepals three. Commonly the perianth is a aer 
relatively large, and the two whorls of 
similar texture. Throughout the flower the members of 
successive whorls are alternate. 
536. The flower structure here reached appears to be 
typical of the great body of the Monocotyledons; and the 
structural peculiarities of the following orders are only 
modifications of those of the Lilies. 
537. Calla Lilies (Arales). In the Calla Lilies the 
individual flowers are small, and massed on a thick 
