8T8TEMATI0 ARRANGEMENT OF ANQ108PERM8. 321 



Thalamiflorse. From this general type evolution appears 

 to have been by two methods, viz., (1) a simplification 

 of the floral structure by the decrease of floral leaves, 

 stamens, carpels, and ovules, as in Aroids, Palms, Sedges, 

 and Grasses in the Monocotyledons, and the many apetal- 

 ous families of the Dicotyledons, and (2) an increase in 

 the complexity of structure of the floral leaves, their union 

 with one another, and the adaptation of the whole flower to 

 insect agency in pollination, culminating in the upgrowth 

 of the stamens and floral leaves around and above the 

 ovary, so that the latter is inferior in the mature flower. 



550. Accordingly we must regard a gamopetalous flower 

 whose structure is otherwise similar as higher than one 

 with separate petals. So too the flower whose ovary is 

 inferior is higher than one of like structure having a 

 superior ovary. It follows that a flower with an inferior 

 ovary and also a gamopetalous corolla must be held as 

 highest in structure. 



551. It is here assumed that the apocarpous Ranales and 

 Resales represent the primitive Dicotyledonous types, and 

 that from these, syncarpy was quickly reached along two 

 divergent genetic lines, viz., the Thalamifloral and the Caly- 

 cifloral. From the former gamopetaly was attained (from 

 that fruitful sub-order the Caryophyllales), resulting in 

 the Primulales, Polemoniales, and related sub-orders in the 

 Heteromerffi and Bicarpellatse. Epigyny was not reached 

 in this genetic line, except in a few aberrant families. In 

 the Calyciflorse the evolution of the flower quickly reached 

 epigyny, this being accomplished long before the appear- 

 ance of gamopetaly (in the Inferse), but here again in 

 certain aberrant families gamopetaly was temporarily 

 attained in the Calyciflorse. 



