The Principles of Morphology. 133 
perceives how very much more natural and easier this theory of 
Celakovsky’s is, than those either of Bower or of the adherents of 
the “ homologous” view, for in the processof its application, it does 
not violate, as both the other theories appear to do, the basic first 
principles of morphology. These demand that, if any two organs 
or structures are to be regarded as homologous, it must be shewn 
that the two bore a common origin, and that there exists an easy 
gradation in the characters of form and structure between the two; 
in other words, that the one can arise by means of easy transfor¬ 
mation of the other. I maintain that these conditions are afforded 
in the embryological data cited above, but that the theories of 
Bower and of the supporters of the “homologous” theory are 
without them. The latter have never brought forward a single instance 
in which the one generation graduates, either as regards structure, 
function, or genetic development, into the other; i.e., no real homo¬ 
logous relationship between the two has ever yet been established.* 
As regards Bower’s brand-new contrivance for creating foliar organs ; 
it has no basis in any similar performance that has ever happened 
previously. The same may also be said with regard to his scheme 
for endowing the apex of the sporogonial capsule with tissue-forming 
facilities! I ask: where are the originals and where is the primitive 
substratum for all this ? 
Hence we see that the leafy stem, considered as a monopodium, 
is a purely secondary structure, and that primarily and in essence 
it is a sympodial construction, consisting of a succession of phytons 
branching one out of another, which are nothing more nor less than 
vegetatively developed sporogonia. In this way only could the 
leafy stem have been built, for that a structure of limited growth, 
like the sporogonium, could give rise to the stem out of its own 
tissues in the way Bower supposes is a quite unreasonable 
supposition. 
The three morphological categories of organs, viz., the leaf, 
stem, and root, which have persisted and remained distinct each 
from the other ever since the antiphytic generation attained any 
development find their natural origin, therefore, in the capsule, seta, 
and/oo^or sucker respectively of the primitive Bryophytic sporo¬ 
gonium. They have become more and more distinct from each 
other ever since. 
These are my views (derived chiefly from a study and appre¬ 
ciation of Celakovsky’s luminous writings), as to some of the 
principles of morphology underlying the evolution of the higher 
plant. W. C. WogsDELL, 
