AND LIFE-HISTORY OF A TROPICAL EPIPHYLLOUS LICHEN. 99 
must probably be looked upon as of the nature of antherozoids, remarkable as this may 
appear. But if this be so, where is the female reproductive organ ? 
Not to carry speculation to absurd limits, it is conceivable that this has not yet been 
discovered ; or, since negative results are of little value, the very complex “ fertile hair ” 
may prove to be in reality the female organ, and a process of fecundation is yet to be 
looked for prior to or after its extension. I have entered thus into the realm of supposi- 
tions, chiefly to show in what direction some highly interesting though very difficult 
investigations may be accomplished by those fortunate enough to be working on the 
spot *. 
THE FUNGUS, AND FORMATION OF THE “ LICHEN." 
On the upper surface of the leaves of Michelia fuscata, especially during the rainy season. 
there may almost invariably be observed copious networks of mycelial filaments, branch- 
ing and anastomosing in all directions; similarly also on the leaves of Thea, Anona, 
Citrus, and the other plants enumerated at page 88, as well as on many other plants 
examined. Putting aside certain Fungus-forms the life-history of which is more or less 
known, and a few others occurring locally, as well as isolated spores not investigated, 
there is one form of mycelium so abundant (especially on Michelia), and so universally 
associated with the presence of the Lichen to be described, that one would be justified in 
pausing to consider it for this reason alone. The hyphe of this mycelium present all 
the well-known characters of an ordinary Pyrenomycete. They are segmented into joints 
of nearly equal length by firm cross septa, and are copiously branched and anastomosed, 
and preserve a pretty constant diameter as they course over the surface of the leaf. The 
cell-walls are firm, and, when fully developed, brown or sepia-coloured. In Pl. XXI. fig. 61 
is a portion of such mycelium as commonly observed. No haustoria have been found in 
connexion with the hyphæ ; and in no case, so far as my knowledge goes, do the fila- 
ments enter the leaf of the plant, either through the stomata or otherwise. Two 
important facts have been made out in connexion with this mycelium. It springs from 
an oval, uniseptate spore, as figured in fig. 67 ; and it is apt to produce clusters of conidium- 
like bodies, such as are represented in fig. 56. These peculiarly dense radiating groups 
of spores are very common and very characteristic; and by their means (apart from the 
definite characters of the hyphe themselves) the mycelium in question can be readily 
recognized at any time. 
Occurring, as this mycelium does, so generally on the leaves of Michelia, &c., on which 
the above-described Alga is flourishing, there сап be no surprise that the hyphe occa- 
sionally, or even frequently, come across the thallus of the latter, and sometimes spread 
over its surface to a greater or less extent. 
This occurs, in fact, very commonly indeed ; and it is somewhat rare to find an Algal 
thallus in the wet season without more or less of the encroaching Fungus on or near it. 
Such has occurred in the example figured іп Pl. ХХІ. fig. 56 and also in РІ. XX. 
fig. 27, a & b; the latter case is also extremely соттоп ; the Fungus-hyphee, invading the 
Algal disk, and creeping up the hairs, produce their dense clusters of conidia around the 
latter, as represented. These phenomena are, I repeat, very common, and can be readily 
* The above account should be compared with Mr. Cunningham’s paper referred to 1n detail below, p. 108. 
