ON LICHENOUS FRUCTIFICATION ON ALG, 3l 
whatever ; those who hold such a view must take refuge in 
the assumption of the formation of the first gonidium in the 
germination of the spore—a process which has not yet been 
observed in any lichen, and, @ priori, never will be. 
But it must be pointed out that, according to Schwendener 
and others, Scytonematous and Sirosiphonaceous alge are 
claimed as forming ‘ gonidia”’ under two distinct circum- 
stances or conditions: they are, according to their researches, 
to be found in certain Lichens either as mere accidentally 
detached portions of filaments wholly surrounded and in- 
volved by the hyphe and caught up bodily in the substance 
of the lchen-thallus in a completely disorderly manner, or 
they exist as perfect plants of their type as alge, the alga- 
thallus quite unaltered in outward configuration, but per- 
meated along the length of the filaments by the hyphae, 
which run between the rows of green cells. When the alge, 
as is assumed, are in the former way compelled to become 
the “ gonidia-formers,” it is the hyphe (not the alge) 
which must be held to control the configuration of the 
thallus and determine the characteristic build-up of the 
‘lichen ;” when the alge serve in the latter way as 
gonidia to the intruding hyphe, the former (not the hyphe) 
retain their proper “ specific ” exterior, the build-up of the 
(algal) thallus is not externally altered and it is only a 
microscopic examination which would reveal anything 
unusual or offer any “lichenous” indication. It is as 
regards this latter gonidial condition that Schwendener’s 
arguments, as to the impossibilty of the genetic relation- 
ship of the hyphe and the young apical gonidia, by reason 
of the latter being formed prior to the arrival at the apex 
of the hyphal filaments, are directed, and to this condition 
it is that the notes here brought forward apply. 
One of the most common of the Scytonemacee is the 
Scytonema myochrous, forming silky cushion-like tufts on 
wet rocks, when dry of mouse-colour, when wet more of an 
olive hue; it seems to love best a pretty constant trickle, 
and if the force of the little current be somewhat strong 
the mass may form a rather long drawn-out pad stretch- 
ing down the inclination of the surface over which the 
httle flow descends. Very often in my searchings I gathered 
little portions from various sites, sometimes very wet, 
sometimes indeed dried up by drought, and once only was I so 
fortunate as to find examples showing apothecia. I regret 
I have mislaid my rough drawing of the apothecium itself, 
but fig. 1 is a sketch of the spores within an ascus. 
‘The general appearance of the apothecium, however, is like 
