84 Prof. F. Schmitz on the 
hesitate to interpret this process in Gl@osiphonia as a sexual 
act, if it were not that in the developmental cycle of this 
species there was already another process which must be 
regarded as a process of sexual fecundation. To assume a 
double act of fecundation in the developmental cycle of a 
single species is, however, in complete opposition to botanical 
conceptions,—that contradicts all tradition *. 
But before the power of facts tradition must always give 
way. As a matter of fact the state of the case is that in 
Gleosiphonia the above-mentioned processes possess all the 
characters which have elsewhere been reckoned requisite for 
a sexual act. There is therefore nothing for it but either to 
embrace as a character in the definition of a sexual act, that it 
can occur only a single time in the developmental cycle of a 
species, and that of two processes, both of which possess 
the other requisite characters of an act of fecundation, only 
one is to pass as a sexual act; or to admit that in the de- 
velopmental cycle of Glaosiphonia (and all analogous Flori- 
dew) a sexual act is twice intercalated, a fecundation of the 
auxiliary cell following after the fecundation of the carpogo- 
nium. 
But if this amalgamation of ooblastema-cell and auxiliary 
cell must be recognized as a sexual act, there is thus thrown 
avery peculiar light upon sexuality in general. For here, 
among the Floridee, the comparison of the different genera 
shows distinctly that the process which in Gleosiphonia dis- 
plays all the characters of a sexual act, is to be referred, as it 
is distinctly observed in variously nearly allied Floridez, to a 
simple act of nutrition, and has evidently originated from such 
a simple act of nutrition. In this way then sexual fecunda- 
tion is tacked on to the simple vegetative nutrition of one cell 
* Certainly Pringsheim (Jahrb. f. wiss. Bot. xi. pp. 18 e¢ segg.) has 
already distinguished, in the fecundation of the Thallophyta (and espe- 
cially of the Floridez), two distinct acts, which he indicates as “ con- 
jugation” and “connubium.” But this distinction simply divides the 
individual sexual act into two steps, while in the present case we have 
actually to do with two separate sexual acts. 
+ At the same time it appears from the preceding description that the 
actual course of the second process of fecundation is somewhat different 
in different cases. In some instances (Gleosiphonia) this process takes on 
the form of a complete union of two cells; in other cases (Ceramieze &e.) 
it would almost appear, as has already been pointed out, that in place of 
such an open conjugation the protoplasm (or the cell-nucleus) of one cell 
migrates through the separating membrane into the other cell. In this 
case the process of fecundation would display exactly the same differences 
which haye been recently demonstrated by De Bary (Beitr. zur Morphol. 
und Physiol, der Pilze: 4te Reihe) in the fecundation of the Perono- 
sporese (Pythium, Phytophthora, Peronospora). 
