594 
Brooks .— The Development of 
of a spermogonium. In addition to this anomalous behaviour, trichogynes 
have also been seen undergoing further development as vegetative hyphae 
(Fig. 13). Such behaviour of the trichogynes militates strongly against the 
view that they are functional receptive organs. The question of their present 
function will be considered later. 
Careful search was made amongst the ascogonial cells of the ‘ coil 5 to 
see if there was any fusion of nuclei in pairs similar to that which takes 
place in the ascogonium of Humariagranulata described by Blackman and 
Fraser ( 3 ), or in the more similar multicellular ascogonium of Ascophanns 
carnens recently described by Cutting ( 7 ). No such process, however, was 
observed. 
The £ coils ’ may develop into perithecia in the autumn or may remain 
throughout the winter in the same condition. Fig. 15 shows a section 
through a portion of a £ coil ’ in the resting stage. It will be noticed here 
that two types of cells are present, viz. those with dense cytoplasm and 
large nuclei, and those with highly vacuolate protoplasm and smaller nuclei. 
I conclude that the former are the cells previously described as being 
ascogonial in nature. Fig. 16 also represents a section of a ‘ coil ’ in the 
resting condition. 
The Development of the Perithecium. 
Frank states that the perithecia develop from the £ coils 5 in the autumn, 
though he suggests that the asci do not ripen until later. My experience 
has been, however, that there is no one definite time for the development of 
the perithecia from the £ coils ’. The change of £ coils 5 into perithecia has 
been found to occur as early as November, while in other cases resting coils 
have been seen as late as March. 
The first thing to be observed in the further development of the £ coil ’ 
is the growth of cells in the lower middle part, i. e. the region which is remote 
from the trichogynes. The cells in this position send out branches which 
grow towards the lower epidermis of the leaf. A few of the cells above are 
often seen to be disorganizing. About the same time the cells towards the peri¬ 
phery of the ‘ coil ’ increase in number, thicken their walls, and thus become 
differentiated at an early stage to form the wall of the perithecium. These 
cells contain food reserves which are probably of an oily nature, since 
they blacken with Flemming’s fixative ; the protoplasmic contents, how¬ 
ever, of these cells are poor. A cavity has by this time appeared towards 
the upper part of the developing perithecium. This is formed probably as 
the result in the main of the greater expansion of the outer tissues. 
It is a matter of great difficulty at this stage to trace the remains 
of the ascogonia. Only occasionally does one find at the periphery of the 
perithecium an unusually large cell containing nuclei of about the same size 
