Gnomonia ery thro stoma, Pers. 599 
The single process of reduction in the ascus is in harmony with the 
single nuclear fusion which appears to occur in this form. 
General Considerations. 
From the observations recorded earlier in the paper, one is led to 
conclude that the £ coils * develop into perithecia without undergoing any 
process of fertilization by means of the spermatia. It is possible, of course, 
that this process has been missed. Even if such a fertilization did occur, it 
would be extremely difficult to demonstrate, both on account of the collec¬ 
tive grouping of the trichogynes and the intricacy of the coiled structures. 
In view, however, of the care which has been taken in order to obtain the 
earliest stages of development of the sexual organs, I do not think this pro¬ 
cess can have been missed. As has been said before, the mere adhesion of 
spermatia to the trichogynes is no evidence that fertilization occurs, for 
under the conditions of growth it would be surprising if most of the tricho¬ 
gynes did not have spermatia attached to them. Besides, it is difficult to 
imagine how the spermatia can pass down to the ascogonial cells in view of 
the fact that no pores appear to exist in the cell-walls between the tricho¬ 
gynes and the cells beneath. 
The most probable view is that the spermatia were originally the 
agents of fertilization. Their cytological characters and other evidence in 
regard to their behaviour point to this conclusion. The spermogonium of 
Gnomonia is to be looked upon as a sorus of functionless male organs 
similar to that which is so often found in the Uredineae. Such a collection 
of male organs may perhaps be compared to the male conceptacles of 
certain Florideae (e. g. Corallina ). 
The trichogynes are looked upon as having originally functioned as 
receptive organs for the ascogonial cells, though my observations indicate 
that they do not thus function at present. Other functions have been 
attributed to the trichogynes which are present in certain Lichens, e. g. Col- 
lema , Physcia. Thus Van Tieghem ( 30 ) considered that the trichogynes of 
these Lichens were really respiratory organs. It is difficult to conceive that 
this was the original function of such trichogynes because there are many 
Lichens and innumerable Rusts, and other fungi parasitic on leaves, which 
at present exhibit no trace of such structures. Lindau ( 26 ), on the other 
hand, assumes that the trichogynes in the case of the Lichens serve a 
mechanical function in preparing apertures for the ascocarps which arise 
later. This explanation will not account for the occurrence of trichogynes 
in Gnomonia where the perithecia are not developed until after the ‘ coil ’ 
has undergone a prolonged resting stage. Though I consider the original 
function of the trichogynes was that of receptive organs, it is possible that 
they serve at present some secondary purpose. Thus, the production of 
trichogynes which have no connexion with ‘ coils ’ may be explained by their 
