29 
AGARIC TRANSFORMATIONS. 
By M. C. Cooke. 
It is still a problem whether—and to what extent—Hymeno- 
mycetal fungi may be modified in respect of their chemical 
constituents, by the soil in which they grow, or the circum- 
stances by which they may be surrounded, There are a few 
pertinent facts, which have led me to the conclusion that close 
observation is necessary, and the record of illustrative 
phenomena would be useful, in determining whether Agarics, 
belonging morphologically to the same species, from which 
they do not appear to vary externally in the slightest appreci- 
able degree, may not sometimes possess properties which 
prevent their use as articles of food, and at other times be 
perfectly harmless and edible. In point of fact, can we believe 
that an Agaric which normally is acrid, and injurious as an 
esculent, may be developed under other circumstances, with the 
same external features, but which is devoid of any acridity, and 
is mild and agreeable, and may be eaten with impunity. The 
question to be determined is, whether we are to regard these 
two forms as modifications of the same species, or whether the 
difference should constitute a specific distinction. 
I may be permitted to illustrate my meaning by an appeal to 
examples. Most practical mycologists are aware that the 
typical form of Russula rubra (Cooke Handbook, No. 1,203) 
is intensely acrid, and js generally characterized as poisonous ; 
whereas I have found, more than once, specimens which possess 
all the characters of the original species, except that they are 
mild to the taste, and may be eaten without inconvenience 
(compare “ Illustrations ” plate 1,025, and plate 1,087). The 
latter corresponds to the Russula atropurpureus of Krombholz 
(pl 64, figs. 5-6), and has been called by me RussuZa rubra var. 
sapida. Krombholz calls it “ mild.” 
Another instance may be found in RussuZa fetens (Cooke 
Handbk. No. 1,216), which, in its normal condition, is wel] 
known by its characteristic external features, as well as by its 
acrid taste, and repulsively foetid odour. What are we to sa 
of the specimens which I have met with, and submitted to the 
judgment of friends around me, which precisely resemble the 
typical species in everything else, but which Possessed no 
acridity to the taste, and were not only quite free from any 
