The Principles of Morphology. 129 
and represent the two opposed facets of the dual whole, each with 
its distinctive character and function. At first the sporophyte 
generation is subsidiary in development to the sexual, as in the 
Bryophytes. Gradually, for purposes of economy, the pendulum 
swung to the other extreme as the sporophyte evolved apace, until, 
as in the Fern, nothing could be more striking than the contrast 
exhibited between the sexual “prothallus” and the strong-growing 
neutral Fern-plant. Are these homologous ? Finally, the sexual 
generation, as in Phanerogams, entirely lost its footing as an inde¬ 
pendent plant, and became completely absorbed into the sporophyte ; 
and there it is unto this day. 
In the antiphytic generation there obtains an interesting homo¬ 
logous alternation of generations between the different kinds of 
shoots on one and the same plant, viz., between the vegetative and 
the reproductive shoots ; here, as in the homologous generations of 
the Algae, the distinct generations agree as to their mode of 
development and habit, yet differ widely in their respective functions. 
II. Origin of the Sporophytic Shoot. 
As all higher vascular plants must belong to the antiphytic 
generation we must now enquire how the primitive sporogonium 
gave rise to the leafy shoot. Bower’s hypothesis is this: that 
sterilisation of the sporogonial head occurred, such that the sporo- 
genous became transformed into vegetative tissue; further that 
this sporogonium became itself the main axis of the future stem, 
while lateral appendages, the future foliar members, were formed 
by means of lateral projections into space from the said sporogonium, 
to which the sporogenous tissue became relegated. Now this view 
seems to me quite untenable. For Bower clearly endows the modern 
foliar organ with the character of a “ morphological Melchisedec.” 
That such a highly-distinctive, morphologically-concrete and 
assertive organ as the “ phyllome,” should have had no parentage, 
i.e. should have developed, unlike all other known organs, out of no 
pre-existing organ which in any degree whatsoever resembled it in 
character—this appears highly unnatural; no analogy for it is 
anywhere to be found. It is surely quite an artificial conception 
of phylogenetic origins which we are asked to entertain. No ! the 
primitive foliar organ could only have arisen by means of easy trans¬ 
formation out of an organ not altogether dissimilar from it which was 
already on the scene; and this organ was the sporogonial capsule. 
This process is very different from that of the projection from the 
