478 MORPHOLOGY. 
thoroughly recognised that little need be said on that 
score, save to repeat that the homology of the floral 
organs is usually not so much with the entire leaf as 
‘ with its sheath. 
The most singular instances of morphological identity 
are those relating to the sexual organs. We have seen 
the gradual transition of stamens to pistils, and of pistils 
to stamens, the development of ovules on the edges of 
the anther, the co-existence of pollen with ovules on an 
antheroid body, and, stranger still, the actual develop- 
ment of pollen within the tissues of the ovule itself! 
From such facts, in addition to what we know of 
the relative position, internal structure, and mode of 
development of the organs, it 1s impossible to avoid 
coming to the conclusion that, however distinctly these 
parts may, under ordinary circumstances, be set apart 
for the performance of distinct functions, morpho- 
logically they are homologous. 
These ideas may be carried yet farther—the same 
sort of evidence, which is adduced in support of the 
morphological identity of leaves with the parts of the 
flower, may be advanced in confirmation of the opinion, 
that, morphologically, there is no distinction between 
axis and leaf. The leaf, according to this view, is a 
specialised portion of the axis set apart to do certain 
work, just as the petals, stamens, &c., are leaves told 
off for distinct uses. It is unnecessary to refer to the 
intermediate productions linking the leaf-form to that 
of the axis, all that is requisite here is to pomt out | 
the facts that teratology lends in support of these views. 
These may be summed up by the statement that almost 
all those attributes which morphologists recognise as 
peculiar to one or the other organ respectively, may 
be and are manifested by both. We have the stem 
acquiring the characters of the leaf, and the leaf those of 
the stem. Thus we have seen leaves, leaf-buds, branches, 
and fiower-buds springing from leaves or leaf-organs ;' 
see pp. 174, 177, 445, &. The structure that we 
1 An additional illustration of this may be cited, which has been 
