OBSERVATIONS ON PEZIZA. 
By M. C. Cooke. 
It is manifestly an advantage, in whatever work we may be 
engaged, to pause occasionally, and take a calm and quiet retro- 
spect, and, it may be, indulge in some reflections upon what has 
been attempted or achieved. It is with some such a feeling that we 
have been led to look over the volume of “ Mycographia ” which 
was recently brought to a close ; and before we again proceed with 
that work, there are some reflections which it may not be deemed 
wholly inappropriate for us to communicate. They must be accepted 
as suggestive rather than dogmatic, and rather as subjects to be 
thought over than questions fully determined. 
In order to assist in this retrospect it may be as well, in the 
first instance, to indicate what we conceive to be the principal 
features in Peziza which are necessary to be taken into account in 
the determination of a species, but before doing so we would quote 
two or three short sentences, written by one of the most persistent 
thinkers on these subjects, which in some measure induced us to 
enter upon these observations. “ In genera having more than the 
average number of species in any country, the species of these 
genera have more than the average number of varieties.” “ In 
large genera the species are apt to be closely, but unequally, allied 
together, forming little clusters round certain other species.” 
“ Species very closely allied to other species apparently have re- 
stricted ranges.” “ No one supposes that all the individuals of the 
same species are cast in the same actual mould.” “ Individual 
differences generally affect what naturalists consider unimportant 
parts, but parts which must be called important sometimes vary in 
the individuals of the same species.” “ The amount of difference 
considered necessary to give any two forms the rank of species can- 
not be defined.” These axioms are placed at the head of our ob- 
servations, without any regard to sequence or comment, as they will 
have to be referred to hereafter. And now to return to the prin- 
cipal features which are to be considered in the determination of 
species in the large genus to which the larger portion of the first 
volume of u Mycographia ” is devoted.* 
1. Habitat. Although no one could be so rash as to assert that 
a species is dependent on its habitat, that fact must be taken into 
consideration. It may happen that the individuals of a certain 
species have invariably been found growing upon the naked ground, 
but should a closely allied form be found flourishing on 
rotten wood, or dung, or a plastered wall, this circumstance would 
be taken into account, not by itself, or on its own merits alone, but 
* And yet less than half the number of species known to us have at pre- 
sent been illustrated. 
