217 
by the Agency of Insects. 
4. The Phalloidei Generally. 
It is however in the Phalloidei, the group to which Phallus 
belongs, that we find the most striking and curious instances 
of deviation and modification for the purpose of adapting them 
for the attraction of insects. Their chief and central character, 
from the point of view of function, is the production, as in 
Coprinus , of a dark, usually foetid fluid, which contains the 
spores; but this leading feature is supplemented and aided by 
the development of a receptacle, remarkable and very various 
in shape, colour, and structure. 
The Phalloidei are pre-eminently an order belonging to 
warm countries, the greater number of the species being con- 
fined to tropical or subtropical regions, where of course insect 
life is most abundant. Although they are widely distributed 
in these regions (vide Table II), we have only four species in 
Britain, and only one that is at all common, namely Phallus 
impudicus. 
They are characterised by the development of the hyme- 
nium within a complete volva, usually subterranean and 
possessing an intermediate gelatinous layer 1 . When the 
spores are mature and ready for dispersion the volva is rup- 
tured by the rapid mechanical expansion of the receptacle, and 
the hymenium deliquesces, darkens, and generally becomes 
foetid. The phenomena connected with the exposure and 
liquefaction of the hymenium are usually very rapid. 
If we consider the character of the receptacle after its escape 
from the volva we find that it presents considerable variety of 
1 To this glutinous layer, which appears at an early stage, before the formation 
of the hymenium, various functions have been assigned. It is often regarded as 
serving to support the expanded receptacle by clasping it after the rupture of 
the peridium. But it is probable that it may have a protective or defensive 
function against the attacks of insects ; for while many or most of the Agarici and 
other Hymenomycetes in the wood where Phallus grows are ravaged by insects or 
slugs, I have not found an example of the volva of the latter being attacked, 
although the stem after its emergence is sometimes eaten by slugs. That v the 
interior is nutritious is shown by the case above cited, in which the maggots no 
doubt made their way in by the base, where the gelatinous layer is absent, and 
which is normally always concealed underground. 
Q 2 
