OBSERVATIONS ON PEZIZA. 
134 
We are not advocating the exclusive use of the sporidia, or any one 
organ, in characterising a species, but, whatever others may be 
omitted, we regard these as essential to a complete character. 
The form of the sporidia may vary within certain limits even in 
the same individual, but never to any considerable extent ; what 
may be called the type of sporidia remains the same, whether 
elliptical, oval, globose, cylindrical, fusiform or linear. The size, 
nevertheless, may vary to a greater extent. It is noticeable that 
the proportions of the long to the short axis seldom undergo any 
great change in the same species when the sporidia are broad. 
When the sporidia are narrow or cylindrical, the variation is usually 
one of length. Compared with other fungi, the fructification of 
the Pezizce exhibit no disadvantage ; the uniformity in each species, 
of both size and form, are quite equal to that of the same organs 
in any other of the Ascomycetes. 
The epispore is sometimes smooth, at others warted, spiny or 
reticulated. These forms are usually regarded as sufficiently 
stable to hold high rank in the essential character of a species. It 
may be safely affirmed that this feature is much more reliable than 
the septation of the sporidia in the Pyrenomycetes. 
As to the contents of the sporidia, little can be said. We are 
well aware of the fact that some excellent and careful mycologists 
attach a considerable weight to the absence, presence or number of 
nuclei (so called) which characterise the sporidia. We never 
shared their faith in nuclei. After many years’ experience, we still 
see no reason to alter this opinion. We have many times mechani- 
cally caused all the nuclei to disappear or be absorbed in the 
specimen under treatment. We have seen them three times as 
numerous in the sporidia from a given individual on one day as 
they were in the same individual a week afterwards. Tested in 
all ways, there seemed to be no reliance upon them in the large 
species on which our observations were made. Faith thus shaken 
has never encouraged us to renew the examinations, or place re- 
liance where we did not deem it deserved. 
The number of sporidia in each ascus scarce needs mention, as 
eight is so uniformly the normal number, that tetrasporous forms 
are rare, so rare, indeed, that we have no opportunity of ascertain- 
ing whether such species as P. tetraspora are ever octosporous. 
Coloured sporidia occur but rarely, and it need hardly be said 
that the species in which they are found can dispense with many 
other distinctions, and rely upon that as almost all-sufficient. 
There is but one other point which calls for remark. The 
“ gelatina hymenea,” so strong in Lichens, is seldom observable in 
the Discomycetes, because uncoloured or weak, and then chiefly in 
Ascobolus. In a few of the medium-sized Pezizae, it is distinct, 
and particularly in P. Phillipsii and P. jungei'mannice. The rarity 
of any distinct intimation of its presence, imparts to this feature a 
value which it does not possess intrinsically, and only acquires on 
account of its rarity. 
