the Ascocarp in Monas cits. 185 
is a large deeply-stained central hypha with many prominent 
nuclei, and around this, in a circle, are other smaller hyphae 
which seem to arise as lateral branches of the central hypha 
(see Figs. 23-27). In young stages there appear to be three 
main hyphae in the cavity, one the prominent central hypha, 
and the other two springing as opposite branches from this. 
The main central hypha thus seems to branch in a manner 
similar to that of the main investing hypha. Each of these 
hyphae branches freely later, and produces within the cavity 
a densely-woven mass of hyphae of various sizes. Only the 
small, young hyphae then stain deeply, the older ones becoming 
quickly filled with large vacuoles and staining but little. In 
later stages these swell so much and are almost unstained, so 
that it becomes impossible to trace their course. 
As the ascocarps increase in size, the size of the cavity in 
the central cell becomes much greater and the mass of hyphae 
within it very considerable. The central cell, in a sense, seems 
to develop accordingly, so that the whole ascocarp is composed 
practically of a solid tissue. A section across such an one 
shows an external ring of investing hyphae, very much 
flattened out and consisting of very little more than cell- 
walls ; these are not contiguous, so that the ring is incomplete : 
then comes a complete ring of tissue, consisting of a section 
across the central cell ; it has both an outer and an inner wall, 
and is of varying thickness. In most sections, completely 
enclosed by this ring, is the central cavity, filled with branching 
hyphae of various sizes (see Figs. 25-32). 
After this stage degeneration seems to take place in the 
ascocarp. The internal hyphae become mixed up with a 
structureless substance, probably mucilaginous in nature* and 
produced by the breaking down of some of the older ones. 
Some of the branches swell up into spherical bodies, the 
young asci, in which eight small darkly-stained round masses 
appear. These are the early stages of the spores. They 
increase in size and eventually become developed into ripe 
spores, ovoid in shape, with pointed ends and thick walls. The 
wall of the ascocarp consists now of a complete brownish 
