40 6 C tilting. — On the Sexuality and Development of 
to be a mucilagenous degeneration were seen in the lighter portions of the 
pad, and it was thought that perhaps the wall underwent some sort of 
mucilagenous change brought on perhaps by the action of some substance 
or substances originating in the granule, but as a similar appearance is seen 
in the basal vegetative cells, and here no secondary pores are formed, 
it seems likely that this appearance has a different meaning. 
The observed facts seem to me to suggest that the pads act, in some 
way, on the transverse wall, resulting in that portion of the wall on which 
they are seated coming away with them. This may perhaps be due to some 
weakening action on the periphery of this portion of the wall. 
Fertilization. 
Nuclear fusions were found to take place in the ascogonium, and it was 
in old ascogonia, with secondary pores, that the process was first studied. 
At this period, and also at the time of formation of the ascogenous hyphae, 
the protoplasm is not nearly as dense as in the earlier stages of development, 
and the nuclei are more easily differentiated. 
The fusion stages are as follows : — A pair of nuclei approach each 
other and touch ; the nuclear membranes, at the point of contact, dis- 
appear, giving rise to the characteristic dumb-bell-like structure. After this 
the nuclear membrane takes on a spherical shape, and inside it are to be seen 
the two nucleoli of the original fusing nuclei (Figs. 8, 9, 10, 11, 12, 13). 
These nucleoli fuse later, going through a dumb-bell stage just as the fusing 
nuclei themselves have done. The fusion nucleus is easily recognized, both 
by its size and by the size of its nucleolus. 
Nuclei in the first ‘contact ’ stages of fusion are very difficult indeed to 
distinguish from nuclei in accidental contact, and such stages are com- 
paratively rarely met with. It is probable that the actual fusion-process 
takes a very short time indeed, owing, partly at least, to the large amount 
of nuclear sap. 
In his paper on Pyronema (20) Harper says that all the fusions take 
place at about the same time, while Blackman and Fraser (7) report that in 
Htimaria granulata the fusions are spread over a long period of time. 
In Ascophanus carneus there are epidemics of fusions, that is to say, the 
fusions seem to last over a long developmental period, and yet when one 
discovers a fusion stage in an ascogonium many others are almost sure to be 
found at the same time. 
It has already been pointed out that no cell in the ascogonium of this 
fungus is specially marked out from the others, either by its size, as in 
Ascobolus , or by any other feature. Corresponding to this, it was found that 
the fusions were not limited to one cell, as has been described in the latter 
genus. 
