221 
sometimes said to belong to the shoot, whereas the parietal 
or marginal ovules, such as are found in the greater part 
of the other Angiosperms, are considered as parts of a leaf. 
It is especially van Tieghem and his followers, who 
have treated the anatomical method, and recently also 
many English botanists attach a great value to the 
vascular-supply, and form their morphological conclusions 
accordingly. However constant the vascular-supply may 
be in many cases, we may not, as to my opinion, lose 
sight of the fact that these organs are always secondary, 
that a leaf does not originate for the sake of a vascular 
bundle, but that a vascular bundle has the function to 
supply the leaf. And though it may be possible that in 
many cases the remaining vascular bundles indicate the 
place of reduced organs they supplied, and thus can 
be used to sustain the other arguments, it is not allowed 
to make far-reaching conclusions from the vascular- 
supply alone. 
Finely the phylogeny though acknowledged as being of 
great importance, has hardly been used by any of the 
former botanists. No one has treated the subject in com- 
paring the same organs of the different divisions of the 
vegetable kingdom to its utmost consequence, which indeed 
was not possible in that time through lack of sufficient 
material. At most the results obtained by a comparison 
of the higher- with the lower-developed plants, were 
accepted as a proof of a once founded theory. 
And yet this manner of research, sustained by the study 
of obvious retrogressive deviations, is the most certain 
mean to determine morphological values. 
It is true that CelakovskŸ takes the phylogeny 
into consideration but his views are wholly based on tera- 
tologicals and ,, Vergrünungsgeschichten” without accoun- 
ting for wether these deviations are really retrogressive. 
Though he acknowledges (33) p. 169 the difficulty of 
