OBSERVATIONS ON TEZIZA. 
136 
radiation, or type. Around this one some twenty others are 
aggregated, presenting differences which can only be accurately 
estimated by a practised eye. It is unnecessary to revive the 
vexed question as to what constitutes a species. “ The amount of 
difference considered necessary to give any two forms the rank of 
species cannot be defined,” and yet such differences will be found 
to exist, whether we call the different forms by the name of 
“ species” or “varieties.” If we are to revert to some such 
catholic notion of a species, as that of its including within it all 
those forms which may reasonably be supposed to have descended 
from a common parent, then all which we have called species in 
the “ red group ” of the subgenus Scutellinia, would be regarded 
as varieties of some original Peziza scutellata from which, in the 
course of generations, the others have diverged. The theoretical 
species is that of a family descended from an original typical pair, 
the practical species is founded on comparison of existing differ- 
ences, which are shared by a group of individuals. The two ideas 
should not be confounded. 
We have in Peziza scutellata , L., a small sessile species, ranging 
from about one-tenth to one-fourth or one-third of an inch in 
diameter. The exterior covered with rigid, more or less elongated, 
dark brown hairs. The disc reddish, to bright crimson. Some- 
times growing on wood, sometimes on the bare ground. The sub- 
stance of the cup fleshy, theasci cylindrical, the paraphyses strongly 
developed, enclosing coloured granules, and the sporidia elliptical, 
about *002 mm. by *012 mm. in size, with an uncoloured epispore 
exhibiting a tendency to become granulated. 
If we accept this as a sufficient character for the species, then 
the whole group, of which P. scutellata is the centre, constitutes 
but a single species. By reference to the figures already given (in 
the work cited) this will be abundantly manifest. If we select 
only those which have a reddish disc it will be found that they 
naturally range themselves in two parallel series, in one of which 
the epispore of the sporidia is smooth, in the other more or less 
rough. The rough spored series will include P. miniata, Fckl., 
P. ampullacea, Limm., P. geneospova, B., P. umhronun , Fckl., P. 
Texensis, B., P. hirta, Schum., P. Cubensis, B. & C., P. badio- 
berbis , B., P. Lusatice, Cke., P. Margaritacea, B., P. vitellina , 
Pers. (the only divergence being in its egg-yellow colour), P. 
crinita, Bull (in which the sporidia become brownish when mature), 
P. strigosa , Pers. and P. labellum , Pers. Here then we have no less 
than fourteen species which agree in the epispore of their elliptic 
sporidia being rough. To these P. stictica, B. & C., might be 
added ; although the epispore is described as punctate, this is a 
point difficult of determination, and the punctate dots resemble 
depressed warts quite as much as depressed puncta. In fact, 
analogy leads to the conclusion that, unless the evidence is strong 
to the contrary, the markings should be regarded as slight eleva- 
tions rather than depressions. 
