ON MIMICRY IN FUNGI. 
11 
The odour of horse radish ( Cochlearia armoracea , L.) is pos- 
sessed by Tuber bituminatum , B. & Br. 
The odour of cucumber (Cucumis sativus) is possessed by Agari- 
cus ( Naucoria ) Cucumis , Pers. 
The odour of ripe apricots ( Prunus armeniaca) is possessed by 
Cantharellus cibarius, Fr. 
The odour of rotting pears (Pyr us communis) is possessed by 
Agaricus pyriodorus, Pers. 
Pilacre Peter sii, B. & Curt., and Hysterangium nephriticum , 
Berk., in its young state, smell like “ some Hypericum.” 
Agaricus frumentaceus, Bull., and 15 other species of the genus 
Agaricus, enumerated in the “ Handbook,” smell like new meal or 
flour, or have a farinaceous odour. 
Animal Odour-mimicries. — Agaricus incanus , Fr., has the 
odour of mice ( Mus musculus). 
Agaricus (Nolanea) pisciodorus, Ces.) has the odour of putrid fish 
(rancid herring).* 
Hygrophorus russo-coriaceus , B. & Br., has the odour of Russian 
leather. 
Rhizopogon rubescens , Tul., “ has when young an acid smell like 
that of sour ham.” 
Hygrophorus cossus, Fr., has the smell of the larvaa of the goat 
moth (Cossus ligniperda). 
Lactarius quietus , Fr., and L. cyatliula , Fr., have the odour of 
the common house bug (Cimex lenticularis). 
Odours of Chemical Compounds. — Agaricus sulfureus , Bull., 
and A. lascivius, Fr., have the odour of gas- tar water. 
Agaricus radicosus, Bull., has the odour of hydrocyanic acid 
(HCN). 
Peziza venosa, Pers., has the odour of nitric acid (HN0 3 ). 
Agaricus alcalinus, Fr., A. nidorosus, Fr., and Hygrophorus 
nitratus , Fr., have odours closely resembling a dilute state of nitric 
oxide (NO). 
Marasmius fcetidus , Fr., has exactly the odour of Cacodyle f 
(C H*| 2 As.). 
What advantage it should be to a fungus to stimulate the 
smell of such poisonous substances as prussic and nitric acids 
it is very difficult to imagine, unless it be for protective pur- 
poses. But the fact that they do so is well known to all mycolo- 
gists. The other odours — namely, of vegetable and animal 
* This it has in common with A. nigripes, Trog., a species not yet re- 
corded in Britain. A. 'pisciodorus is by no means an uncommon species, but 
it is often confounded with A. cucumis, from which it differs both in the 
colour of its spores and in its smell. 
t Cacodyle or Arsendimethyl is an extremely poisonous substance, which 
is prepared by heating arsenious oxide with potassium acetate. It has a 
most disagreeable garlic-like smell. I have never yet come across any 
other fungologist who was acquainted with this compound, but the odour 
of it, to my mind, exactly resembles that of Marasmius fcetidus. 
