An Historical Sketch . 
69 
rash, thinkers who feel themselves at full liberty to compare certain organs 
of the Phanerogams with what they regard as related organs in the Vascular 
Cryptogams. It will suffice to quote a remark from page 11 of his work of 
1875, where he says : ‘ Perhaps the integument (of Cycas) may be regarded 
as the equivalent of the indusium ’ (of Ferns). This view will be further 
elaborated when the tenets of the last author on our list are considered. 
Again, on page 13 he says : ‘ From my point of view I am unable to believe 
in actually axile ovules or anthers ; these organs are derivatives of sori,’ 
which are parts of the leaf. Further, he remarks : ‘ Ovules I must regard 
as under all circumstances originally parts of the carpel.’ 
At first (as seen from his paper of 1872, in which he says : € Ovules are 
certainly most frequently metamorphosed axes ’) a defender of the axile 
nature of the ovule, Warming (46), in his most valuable thesis : ‘ De l’ovule,’ 
published in 1878, and containing a series of researches into the development 
of the ovule-rudiment of the nucellus, unequivocally upholds the Brong- 
niartian theory of the ovule. ‘ In every ovule we have considered two parts 
essentially different : the funicle and the integuments, which are of foliolar 
nature, and the nucellus, which is a new creation, a sporangium, a “ sorus ” 
composed of a single sporangium, as Prantl would say.’ The origin and 
mode of development of the ovule-rudiment is similar to that of leaves, 
leaf-lobes, metablastema, emergences, and buds. Histogeny tells us nothing 
as to the morphological nature of the rudiment ; it only informs us as to 
how the latter arises on the placenta as a new formation. ‘ There is but 
one method which can lead us to the goal : the gradual comparative study 
of allied forms, relying on all the means at the disposal of the morphologist.’ 
On page 195 he writes: * The comparative study of the carpels and placen- 
tation in the entire vegetable kingdom, the scrupulous examination of 
antholyses and the course of the vascular bundles, lead us, as Celakovsky 
and Van Tieghem have recently proved, to the conclusion that carpels and 
placentas are everywhere phyllomes, and that the ovule-rudiment is a 
leaf-lobe ; I do not know if, in certain cases, they should not be regarded as 
metablastema, but the difference between the latter and a leaf-lobe is not 
essential and cannot be everywhere sustained.’ On page 200 he proceeds : 
£ The so frequent foliar transformation of the ovule-rudiment which will 
later become the funicle, and its fusion with the carpel, is indomitable proof 
that this organ is really a leaf-lobe, a conclusion which had already been 
rendered very probable by the position and order of appearance of the 
ovules. Ovules are not buds ; I know of no complete and well-studied 
teratological transformation which absolutely confirms the contrary, and 
I dare add that it will not be discovered. The ovular rudiment is therefore 
a leaf-lobe.’ The developmental history and teratology show us : — > 
1. That the nucellus is a new formation on the ovule-rudiment, which 
is itself merely a lobe of the carpel. 
