POLYMORPHISM. 193 
oval conidia which are solitary on the tips of the threads. 
Therefore this Hypocrea will possess two different kinds of 
conidia, as is the case in many species of Hypomyces. 
A most familiar instance of dualism will be found in Nectria 
cinnabarina, of which the conidia form is one of the most common 
of fungi, forming little reddish nodules on all kinds of dead 
twigs.* 
Almost any small currant twig which has been lying on the 
ground ina damp situation will afford an opportunity of studying 
this phenomenon. The whole surface of the twig will be covered 
from end to end with little bright pink prominences, bursting 
through the bark at regular distances, scarcely a quarter of an 
inch apart. Towards one end of the twig probably the pro- 
minences will be of a deeper, richer colour, like 
powdered cinnabar. The naked eye is sufficient 
to detect some difference between the two kinds 
of pustules, and where the two merge into each 
other specks of cinnabar will be visible on the 
pink projections. By removing the bark it will 
be seen that the pink bodies have a sort of 
paler stem, which spreads above into a somewhat 
globose head, covered with a delicate mealy bloom. 
At the base it penetrates to the inner bark, and 
from it the threads of mycelium branch in all 
directions, confined, however, to the bark, and 
not entering the woody tissues beneath. The 
head, placed under examination, will be found to 
consist of delicate parallel threads compacted to- 
gether to form the stem and head. Some of these ue 
threads are simple, others are branched, bearing Fis. 104. — Twig 
with Tubercularia 
here and there upon them delicate little bodies, on th? upper por- 
tion, Nectria on the 
which are readily detached, and which form the lower. 
mealy bloom which covers the surface. These are the conidia, 
little slender cylindrical bodies, rounded at the ends. 
Passing to the other bodies, which are of a deeper colour, it 
* “A Currant Twig, and Something on it,” in ‘Gardener's Chronicle,” 
January 28, 1871. 
