PHANEROGAMIA. 265 
hibiting several divergent groups, the one containing the 
Asterale Cohort rising highest. In such an arrangement 
the orders of the Apetalz would be placed as degraded or 
simplified offshoots mainly from the Choripetale, while a 
few would doubtless be regarded as directly lower than 
and preceding the latter group. 
537. A great many Dicotyledons show adaptations for 
pollination by insect 
agency, and it is safe to 
say that more than half 
the species are more or 
less dependent upon the 
visits of insects in order 
that their ovules may be 
fertilized. In a general 
way it may be said that 
the showy flowers with 
a bright calyx or corol- yyq. 144. —The Cherry (Prunus cerasus), with 
la, or both, are pollinated °™s**re4 fowers. 
by insects, while those without showiness are wind-polli- 
nated, or close-fertilized. The plants of the Apetalous 
orders are for the most part not visited by insects; few of 
them have bright colors, and few produce nectar. 
538, The simpler Choripetale, as the Crowfoots (Fig. 
148) and their near allies, attract insects by their showy 
perianth, and the nectar they secrete. Cross-fertilization 
is generally secured by a difference in the time of maturity 
of stamens and pistils (i.e, by dichogamy), apparently, 
however, often permitting close fertilization. The same 
is true in general of most of the regular flowered Chori- 
petale. Thus in the Roseworts (Fig. 144), while nectar i ig 
usually abundant and the flowers are generally sweet~ 
