Fertilization of the Floridee. 83 
carpospores. In other cases these ooblastema-threads, for the 
purpose of readier and more abundant nourishment, first of 
all enter into union with the cells of the sterile thallus-tissue. 
In a later stage of fuller differentiation, special thallus-cells, 
the auxiliary cells, are already previously prepared for this 
purpose and abundantly furnished with contents; but the 
ooblastema-cells enter mto a closer and closer union with 
them, which may advance to complete conjugation. Finally, 
the ooblastema-cell unites completely with the auxiliary cell to 
form a single cell, which now, for its part, takes on the func- 
tion of the ooblastema-cell and carries it to completion; and 
at length there is no longer any development of pluricellular 
ooblastema-threads, but the ovicell itself (or a part of it) unites 
with the auxiliary cell. Thus, as the development of a simple 
process of nutrition, there results a process which, in its whole 
course, agrees perfectly with those processes which are desig- 
nated as sexual processes of fecundation. 
If in order to proceed quite securely we limit the discussion 
to the processes of fructification in Gleosiphonia which are 
comparatively easy to ascertain, the union of ooblastema-cell 
and auxiliary cell here shows ail the characters of a sexual 
fertilization. ‘The conjugation of the two cells and the trans- 
fer of the protoplasm of the ooblastema-cell take place in 
exactly the same way as in recognized processes of fecunda- 
tion, for example in the fertilization of Pythium* and Anci- 
listes T ; nay, 1t may even be ascertained that the cell-nucleus 
of the ooblastema-cell unites with the cell-nucleus of the 
auxiliary cell, as finally, after the evacuation of the ooblas- 
tema-cell into the auxiliary cell, only a single cell-nucleus is 
present. ‘The consequence of this union of the two cells is, 
however, a new and very rapid growth of the auxiliary cell 
quite different from its previous growth, a growth which 
never occurs without a union of the auxiliary cell with the 
ooblastema-cell. ‘Thus therefore a// the conditions f are ful- 
filled that can be required of a process which is to be regarded 
as a process of sexual fecundation ; and certainly no one would 
* De Bary, Beitr. zur Morphol. und Physiol. der Pilze. 4te Reihe. 
+ Pfitzer in Monatsh. Akad. Wiss. Berl. 1872, pp. 393, 394. 
} If we leave out of consideration all inconceivable, mysterious, meta- 
physical qualities of sexuality only the following remain as common 
characters of all vegetable processes which have hitherto been by com- 
mon consent recognized as sexual :—union of two (similar or diflerently 
developed) cells with fusion of the cell-nuclei, and a new and peculiar 
mode of growth of the conjugation-cell, which, without this conjugation, 
does not take place. In other respects the generally recognized processes 
of fecundation (to say nothing of the disputed ones) display the most 
multifarious differences. 
