A484 MORPHOLOGY. 
identity of the leaf-form and of the stem-form be ad- 
mitted. 
Structure of the ovale—The nature of the ovule and of 
its coverings has been a fertile source of controversy. 
The teratological data bearmg on this subject have been 
given at pp. 262—272. These data strongly support 
the notion of the fohar nature of the coatings, and of the 
axial nature of the nucleus, taking leaf and axis either 
in the ordimary sense, or as modifications one of the 
other. It has been shown that the ovular coats may 
themselves become carpels, and that ovules may be 
developed upon ovules, p. 268. Whether the intra- 
carpellary siliques of Chevranthus, not uncommonly 
met with (p. 182), are instances of ovular transmutation 
may be open to doubt. 
The axial nature of the nucleus has been inferred from 
its position, mode of growth, and from its occasionally 
lengthening into a leafy or even a floriferous shoot. 
Probably it may occasionally be invested by sheathing 
coats, more analogous to tubular processes from the 
receptacle, than to folar organs, as is the case im 
Welwitschia. The discussion of this matter, however, 
pertains rather to normal morphology than to tera- 
tology. 
Morphology of conifers—'T'he nature of the pseudo-leaves 
of Sciadopitys, and probably of other Conifers, is illus- 
trated by teratolog ey, as also is the true constitution of 
the scale of the cone (see pp. 192, 245, 352), though 
it must be admitted that little or no light is thrown 
on that much-contested point—the true nature of the 
ovule of Gymnosperms. 
Relative position of organs—-When organs are con- 
sidered, not separately, but in their relations to each 
other, the appearances presented are referable to 
similar causes. Thus, the separation of parts usually 
united has been shown to depend on an excess of 
