COROLLA. S77 
requires modification. In the case of polypetalous, or 
rather dialypetalous flowers, the petals may be very 
largely increased by multiplication, as im roses, ane- 
mones, pinks, &c. In the last-named genus the number 
is often so much increased that the ‘ealyx splits from 
the tension exercised on it by the increasing mass 
within. This multiplication may happen without any 
metamorphy or substitution of petals for stamens, 
though, in the majority of cases, 1t is associated with 
such a change. It is curious to observe in some 
of these flowers that the total number of parts is 
not greatly increased ; thus, in some of the double- 
flowered Leguminose, ‘such as Ulex ewropeus and Lotus 
corniculatus, the petals are repeated once or twice, the 
stamens are petalodic, but reduced in number, while 
the carpels are usually entirely wanting. Thus, owing 
to the diminished number of parts in the inner 
whorls of the flower, these very double-looking blooms 
do not contain any greatly increased number of 
parts." 
Flowers that, under ordinary circumstances, are 
gamopetalous, become, in some instances, multiplied 
by the formation of additional segments, just as in the 
case of polypetalous corollas; but in these cases the 
corollas become polypetalous, their petals do not co- 
here one with another. Among double flowers of this 
character may be mentioned Campanula rotundifolia, 
Gardenia sp., Nerium Oleander, Serissa sp., Arbutus 
Unedo, &e. The change is associated with petalody of 
the stamens and pistils. 
A more frequent change among the monopetalous 
orders 1s the duplication or triplication of the corolla, 
in consequence of which there appear to be a series of 
corollas enclosed one within the other, the lobes of 
which generally alternate with one another, but which 
sometimes are superposed. ‘This happens occasionally 
in the primrose (Primula acaulis), and constitutes the 
variety called by the gardeners ‘‘ hose in hose.” 
' C. Morren, ‘ Bull. Acad. Belg.,’ xix, part ii, p. 17. 
