THEORETICAL STRUCTURE OF THE FLOWER. 301 
Thus, if a double Rose be examined, all sorts of transitions may 
be observed between true petals and stamens. In other cases, 
the stamens have been actually transformed into true leaves. 
As far as the stamens, therefore, we have no difticulty in tracing, 
both in the normal and abnormal conditions of the parts of the 
flower, a regular and gradual transition from the ordinary leaves, 
thus forming conclusive evidence of their being developed upon 
a common type with them. 
If we now pass to the carpel, we find that transitional states 
between the stamen and carpel are unknown in the normal con- 
dition of flowers, the difference in the functions performed by 
them respectively being so opposite, that it necessarily leads to 
corresponding differences in structure. We must, therefore, 
look to monstrosities, or deviations from ordinary structure, for 
examples of such conditions. Even these are by no means com- 
mon. Such may, however, be occasionally found in the House- 
leek, some Poppies, and in other plants. In a paper, published 
by the author in the Pharmaceutical Journal for March, 1856, 
a very remarkable instance of this transition from stamens 
to carpels was described ; it occurred in Pupaver bracteatum. 
In this case, several whorls of bodies, intermediate in their 
nature between stamens and carpels, were found between the 
true andreecium and gyneecium. The outer whorls of the in- 
termediate bodies differed from the ordinary stamens, in their 
colour, in being of a more fleshy nature, and in being enlarged 
at their upper extremity and inner surface into rudimentary 
stigmas ; in other respects they resembled the stamens, and 
possessed well-marked anthers containing pollen. The whorls 
next in succession gradually lost their anthers, became more 
fleshy, bore evident stigmas, and on their inner surfaces, which 
were slightly concave, they had rudimentary ovules. Still more 
internally, the intermediate bodies, whilst resembling those just 
described in their general appearance, became more concave on 
their inner surface, and bore numerous perfect ovules: and 
within these, the intermediate bodies had their two margins 
folded completely inwards and united, and thus formed perfect 
carpels. Such an example as this shows in a striking manner 
that the stamens and carpels are formed upon a common type, 
and hence, that the latter are, like the former, homologous 
organs with leaves. The analogy of the carpel to the leaf is, 
however, constantly shown in cultivated flowers, even in a more 
striking manner than the stamen is thus proved to be a modified 
condition of that organ. Thusin many double flowers, as Butter- 
cups and Roses, the carpels, as well as the stamens, become 
transformed into petals. It is by no means rare, again, to find 
the carpels transformed into true leaves in cultivated Roses, &c. 
A similar condition also occurs in the Double Cherry ( Jigs. 587— 
589), and has been already fully described when speaking of the 
earpel ; in which place we have also shown the analogy of the 
