366 PLANT STUDIES 
within the flower, but below it (Fig. 132), and the flower 
is often said to have an " inferior ovary." 
4. From apocarpous to syncarpous flowers. In the 
simpler flowers the carpels are entirely distinct, each car- 
pel organizing a simple pistil, a single flower containing as 
many pistils as there are carpels (Fig. 324, A). Such a 
flower is said to be apocarpous, meaning " carpels separate." 
There is a very strong tendency, however, for the carpels of 
a flower to organize together and to form a single com- 
pound pistil (Fig. 324, B, C), such a flower being called 
syncarpous, meaning " carpels together. " 
5. From polypetalous to sympetalous flowers. While the 
petals are entirely distinct from one another in the lower 
forms, a condition described as polypetalous, in the highest 
Angiosperms they are coalescent, the corolla thus becoming 
a more or less tubular organ (Figs. 73, 74). Such flowers 
are said to be sympetalous, meaning " petals united." 
6. From regular to irregular flowers. In the simplest 
flowers all the members of one set are alike, and the flower 
is said to be regular (Fig. 74, a, I)}. In certain lines of 
advance, however, there is a tendency for some of the mem- 
bers of a single set, particularly the petal set, to become 
unlike. For example, in the common violet one of the 
petals develops a spur ; while in the sweet pea the petals 
are remarkably unlike. Such flowers are said to be irregu- 
lar (Fig. 74, c, d, e), and as a rule irregularity is associated 
with adaptations for insect pollination. 
These various lines appear in all stages of advancement 
in different flowers, so that it would be impossible to deter- 
mine the relative rank in all cases. However, if a flower is 
naked, with indefinite numbers, hypogynous, and apocar- 
pous, it would rank very low ; but if it has a calyx and 
corolla, is completely cyclic, epigynous, syncarpous, sym- 
petalous, and irregular, it would rank very high. 
243. The gametophytes, As in the case of the Gymno- 
sperms, the gametophytes of Angiosperms are exceedingly 
