4 
ON MIMICRY IN FUNGI. 
the rupture or sudden opening of the upper end of the asci, 
which seems to be induced when their tension has attained a 
certain point — the bursting strain. As each ascus ruptures, it 
relieves the tension of the whole hymenium to an extent equal 
to its own diameter, the next ascus does not give way 
until the requisite tension has been regained. Of course the 
integrity of the cup forms an important element in the produc- 
tion of this tension, hence the advantage to Pezizce of availing 
themselves of protective mimicry to guard against external 
injury. This seems further borne out by the fact that the only 
markedly odouriferous Peziza amongst our British species ( P . 
venosa , Pers.) has the concavity of its hymenium broken by promi- 
nent ridges. 
The honey secreted by the flowers of phanerogamous plants is, of 
course, the source of attraction to insects, but this inducement 
does not exist in fungi. The advantages which are derived by 
flowering plants from fertilization by pollen from another indi- 
vidual of the same species are probably equalled by an interchange 
of reproductive elements amongst fungi, and we here find an ex- 
planation of many facts that are otherwise inexplicable. Although 
there is no honey to be obtained from fungi, still there are advan- 
tages to be gained by the visiting insects. The larger Hymenomy- 
cetes are well calculated to afford abundant food to insect larvae, and 
the rapidity with which the fleshy species disappear before the 
voracious appetites of their numberless tenants shows that insects 
fully avail themselves of this source of nutriment for their off- 
spring. But larvae do not feed on all fungi with equal avidity. The 
majority of agarics are so attacked ; some species, such as 
Agaricus rubescens, can hardly ever be found without their bar- 
rows somewhere about it, either in the pileus, in the stem, or espe- 
cially in the bulb. Most of the Russules are greedily devoured — 
even such acrid species as R. emetica and fragilis. The Lactarii , 
on the other hand, enjoy a comparative immunity from insect depre- 
dation compared with other fungi. Insects find their way even 
into subterranean fungi. I have frequently raked up Hymeno- 
gasters and found them full of active larvae. Messrs. Berkeley 
and Broome,* speaking of Tuber bituminatum, B. and Br., say — 
“ Some of the specimens were attacked by worms (larvae ?), the 
flesh of which became quite black when dry.” Tuber cibarvm is 
often preyed upon by a species of Liodes, f to which fungus Aniso- 
toma cinnamonea is also said to be attached. 
Many beetles live in the larger Polyporei and in Sclerodeimna — ' 
Cis Boleti for example. Dr. T. A. Chapman has described J the 
life history of a small beetle — Abdera bifasciata , Marsh — which 
*“ Berkeley and Broome Annals.” Nat. Hist. Series, ii. ; vol. vii, No. 
581. 
+ “ Berkeley English Flora,” vol. v, part 2, p. 228. 
j Chapman, T. A. “Transactions of the Woolhope Club,” 1869 ; p. 161 ; 
“ Entomological Monthly Magazine,” vol. vi, p. 259. 
