122 ASCOMYCETES AND RHODOPHYCEA, 
of contact dissolve, the cytoplasm of the two cells becomes continuous. 
The nuclei show no tendency even to approach each other, but, on 
the contrary, that of the cell of the sporogenous filament seems to 
repel the nucleus of the auxiliary cell, as this one generally retreats 
from its former central position to the side farthest removed from the 
point of contact of the two cells (Fig. 47, E, and Fig. 48, A). That 
part, or half, of the fusion cell which corresponds to the sporogenous 
filament now begins to send out a protuberance into which the sporoge- 
Fic. 48.—Copulation of sporogenous filaments with auxiliary 
cells, and origin of a cystocarp in D, purpurifera.—(After 
Oltmanns.) 
A, a sporogenous filament has fused near its end with an aux- 
iliary cell; s, sporogenous nucleus, az, auxiliary cell. 
B, sporogenous filament after copulating with an auxiliary cell 
has continued its development; protuberance containing 
sporogenous nucleus, sX, will probably give rise to a cys- 
tocarp; 2X, nucleus of auxiliary cell. 
C, a sporogenous cell has been cut off from the filament oppo- 
site point of fusion with an auxiliary cell; sX, sporogenous 
nucleus ; 2X, nucleus of auxiliary cell. 
sk 
D D, later stage; sf,a very young cystocarp. 
nous nucleus and dense ¢ytoplasm pass (Fig. 47, E, sz). In the 
earlier developmental stages following fecundation this protuberance’ 
develops an additional branch of the sporogenous filament which is 
to seek and fuse with other auxiliary cells (Fig. 48, A, B). In case 
of the development of a cystocarp from the fusion cell, the protube- 
rance in question, after the division of its nucleus, will be cut off as a 
rounded cell (Fig. 48, C), which will give rise ultimately to a spore 
fruit. 
In Dudresnya purpurifera the nuclei of auxiliary cells which 
have fused with cells of the sporogenous filaments tend to diminish in 
size and disappear, while in D. coccimea the nucleus of the auxiliary 
cell may remain normal and divide. Inno case, however, do these 
auxiliary nuclei show any disposition to fuse with a sporogenous 
nucleus, 
