110 DR. HOOKER AND DR. THOMSON'S PRECURSORES 
they have perennial rhizomes and annual branches ; a few are suf- 
fruticose, having woody stems and annual branches. The axis 
presents numerous modifications of habit, consistence, surface, and 
extension. Some of the largest suffruticose species (J. Jwrpia, 
fruticosa, &c.) attain 5 feet in height—and perhaps much more— 
resembling acanthaceous bushes in their half-shrubby character and 
tumid nodes; the scapigerous section has been already mentioned ; 
another equally remarkable set of species, as regards their stems, 
includes the succulent-jointed epiphytie peninsular species, Z. Jer- 
donia, viridiflora, &c. 
The morphology of the flower of Impatiens has occupied the 
attention of many observers, who have taken different views of the 
real nature of the pieces of the perianth; we coincide with the 
view taken by Roeper*, Edgewortht, and Henfrey}, and which 
we have ourselves confirmed from numerous observations on the 
living species. There are three independent methods of obtaining 
proof of this view ; and they all appear to us to give the same 
result: they are the following :— 
1. Seeking amongst the species for those with the fullest comple- 
ment of organs, and ascertaining the position and value of the 
supernumerary ones.— The existence of species with four lateral 
sepals was first indicated by Edgeworth, who has pointed out that 
they are figured in the plate of 7. glanduligera (1. Roylei, Walp.) 
in Royle's * Illustrations,’ who, moreover, detected them in other 
species, /. amplexicaulis, &c., and first discerned their significance. 
We may add J. longipes, urticifolia, leptoceras, var. п, sulcata, 
sabrida, and arguta as also having four sepals, but not constantly. 
2. Comparison with a closely allied genus which presents a dif- 
ferent modification of perianth,—as Hydroceras, which at once 
explains Impatiens. 
9. Examination of the relative positions, &c., of the parts in 
single and double flowers, with one another and with the axis—the 
course pursued by Mr. Henfrey. 
All these methods lead to the same result, and appear to us to 
prove that the flower of Impatiens consists of a calyx of three (or 
more rarely five) sepals, of which the two supernumerary are 
always smallest and next the axis ; the two next always green, and 
small as compared with the petals and the odd one, or that away 
from the axis, which is usually coloured and spurred. The corolla 
consists of one erect, often bifid or emarginate petal next the axis, 
* Linnea, ix. 92]. + Linn. Trans. xx. 37. 
t Linn. Journ. Bot. 
