170 
ORGANOGRAPHY. 
BOOK I. 
back of every row, except the in- 
ner. For example, in the follow- 
ing diagram (123.), let O be the 
axis, b h placentae, c c the backs of 
carpels; the placentae, b by of the 
inner row will be next the centre 
O ; the placentae, b J, of the second 
row will be next the backs, c c, of 
the first row ; and so on. 
If the order of developement of 
leaves were exactly followed in that of the stamens and car- 
pels, it would happen that the latter 
0 
0 would be invariably alternate with 
f — the inner row of stamens; for if a a 
1 ^ / \l) i-fi^'^^^') station of five sta- 
mens, b b would be the situations of 
the carpels : this relative position is 
therefore considered the normal one, 
( a) is ^^^^ t^^^ which usually ex- 
ists in perfectly regular flowers; 
but as all the parts of a flower, 
in consequence of the non-developement of some parts, or 
the excessive developement of others, are subject to devia- 
tions, either real or apparent, from what is considered 
their normal state, it frequently happens that the carpels 
either bear no apparent relation to the stamens or are 
opposite to them. In Papilionaceous plants, for example, 
where only one carpel is present, it is difficult to say that it 
bears any exact relation to the stamens, although it is pro- 
bable that its position is really normal with regard to them ; 
and so also in Rosaceous plants, with numerous carpels, no 
exact relation can be proved to exist between the latter and 
the stamens, unless it may be said to be indicated by those 
genera, such as Spiraea, in which the carpels are reduced to 
five ; and, finally, in such plants as Delphinium, in which the 
carpels are three, while the floral envelopes and male system 
are divided upon a quinary plan, it is manifest that no alter- 
nation can exist between the stamens and carpels. 
As the sepals and petals most commonly consist each of a 
