222 
knowing for certain to which cause the deviations are to 
be attributed and which consequences may be concluded 
from, he starts entirely from the supposition that his 
,ovulum-antholysen” are ,,Rückschlagserscheinungen”. 
According to these methods of investigation, but chiefly 
by means of the three first ones, the three groups 
of opinions mentioned in the beginning were formed. 
Worsdell in his paper ,,On the structure and morphology 
of the ovule” (180) has given a review on these different 
theories, in which the ovule is said to have the value of 
a bud or of a leaf, or cannot be classified at all in one 
of those catagories, and which theories can be indicated 
for shortness sake respectively as the axial, foliolar and 
sui-generis theory. 
For a more detailed treatment I can refer to this excellent 
article of Worsdell, and I will confine myself to mention 
only the contents and the names of the followers of 
those views: 
A Xial theory. 
The nucellus is of the nature of a bud and both inte- 
guments are its lateral foliar appendages St. Hilaire, 
Schleident (129); ‘Payer, Braun, "Pevyriteery 
Pearson (113). 
Foliolar theory. 
The ovule belongs morphologically to the category of 
the phyllome; the nucellus is of the nature of an emer- 
gence, borne on the upper surface of a leaflet of the 
carpel, whereas the integuments are the fused lateral lobes 
of the same segment of the female sporophyll. 
Brogniart (26), R. Brown (28), Caspary, Cramer 
(53), Prantl, Warming, CelakovskŸ. 
Sui Generis theory. 
The ovule is an independent structure, borne either on 
cauline or foliar organs. The integuments are new forma- 
tions around the nucelles. 
