140 
OBSERVATIONS ON l’EZIZA. 
the roughness or smoothness of the epispore, in the mature 
sporidium, is accepted as a satisfactory independent basis for the 
establishment of a species. That of two individuals, agreeing in 
every other particular, the one of which has smooth and the other 
rough sporidia, this feature has been held sufficient for their re- 
cognition as distinct species. It is, perhaps, a condition seldom 
realised, of perfect identity in every point save one, and yet, in 
such an extreme case, it is doubtful if any valid objection would 
be urged to the acceptance of the epispore as final. The same 
could not be safely affirmed of any other character. It is the 
only one on which general reliance would be placed. In the face 
of this strong evidence there would appear to be an insuperable 
barrier to regarding the seven species last named as continuous 
with the first series of fifteen ; and yet evidence may be produced 
to prove that in one of the most common of smooth spored species, 
unmistakable transitions may be found. We have examined 
specimens of Peziza scutellata from localities widely apart, from 
Great Britain, several European countries, North America, and 
other parts of the world, and observed with interest the modifica- 
tion of the epispore from a perfectly smooth surface, through 
minute granulation to a most decided warted surface. If it should 
be urged in opposition to this fact, that, according to admission 
already made, the roughness of the spore is an efficient character, 
and that the rough spored and smooth spored P. scutellata are dis- 
tinct species, in reply we contend that we have found the same two 
forms growing side by side, and further, the same two forms co- 
existing in the same individual. The appearance of sporidia 
having a smooth epispore in an individual Peziza , the mature 
sporidia of which are rough, may be explained by the fact that 
immature sporidia do not exhibit the roughness which is char- 
acteristic of them when fully mature. Those who have had any 
extended experience in the examination of the hymenium of Peziza 
are aware that it is often with extreme difficulty that immature 
sporidia can be forced out of the asci in which they are generated, 
and that rough sporidia acquire their roughness before they leave 
the ascus. It is reasonable, therefore to assume that free sporidia, 
which have voluntarily left their asci and are still smooth, are 
likely to remain so, such being their normal condition. When 
free sporidia, with a smooth epispore, are encountered in the 
hymenium of a Peziza and at the same time also sporidia with a 
rough epispore, either enclosed in asci or free, it may fairly be 
assumed that both are the production of the same individual. 
There is one other aspect in which this phenomenon may 
be contemplated. It may be objected that, after all, Peziza 
scutellata is not a smooth spored species when fully matured 
under favourable conditions. That longer time, or certain 
other circumstances are essential for the perfection of the sporidia, 
which only occasionally, and under exceptional conditions, attain 
their highest state of perfection with a rough epispore. To this 
