confluens and the Morphology of the Ascocarp. 347 
equivalent of the receptive spot in the oospheres mentioned. 
That such an area occurs in the male cell as well as in the 
female cell is a further indication, in addition to the facts noted 
above, that the antheridium in this case is not alone the active 
element, a mutual reaction being rather induced between both 
antheridium and conjugating tube. I have not found this 
receptive spot in the antheridium until after the conjugating 
tube was in contact with it at its apex. The corresponding 
area in the conjugating tube is developed as the beak is 
formed. In their late appearance these structures differ from 
the receptive spot in the oospheres mentioned, which by 
some authors have been regarded as centres for the diffusion 
of substances which serve as a chemotactic stimulus to the male 
cell to attract it to the egg. 
The walls of the antheridium and conjugation-tube, at the 
point where the beak of the conjugation-tube is closely pressed 
against the antheridium, break down, and a pore is formed 
leading from the tube to the antheridium. The process of 
solution of the wall seems to be a rather gradual one and 
to consist in the softening and dissolving of the wall-material 
which swells and seems to spread gradually out into the 
protoplasm of the beak. Sections at this stage show the 
hitherto sharply defined walls replaced by a spongy mass, 
which stains deeply with safranin and seems to be diffusing 
upward into the beak as fine fibres or ragged shreds' (Figs. 
8, 9); on the side next the antheridium there is no indication 
of such diffusion of the swollen wall-material into the fine 
granular plasm of the male receptive spot. This perhaps 
indicates that the solvent action on the wall is mainly exerted 
from the interior of the conj ugation-tube. 
Ultimately a circular disk of the walls is entirely dissolved 
away, leaving the roundish pore through which the protoplasm 
of the two cells becomes perfectly continuous. . Irregular 
deeply staining bits of material remain for some time in the 
neighbourhood of the pore representing the swollen but not 
completely dissolved fragments of the broken-down wall 
(Fig. 10). Tulasne and Kihlmann have both noted the 
