07 У 
VII. Onthe Structure, Development, and Life-history of а Tropical Epiphyllous mao 
(Strigula complanata, Fée, fide Rev. J. M. Crombie). Ву H. MansuanL WARD, 
B.A., Berkeley Fellow of Owens College, late Cryptogamist to the Government 
in Ceylon. (Communicated by W. T. Тнтзкоток DYER, C.M.G., F.R.S., F.L.S., 
Assistant Director, Royal Gardens, Kew.) 
(Plates ХУПТ.-ХХТ.) 
Read February 1st, 1883. 
MANY of the facts enumerated in this paper had been already discovered when a paper 
by Mr. D. D. Cunningham оп Мусогдеа parasitica (Linn. Trans. Bot. i. part vi. January 
1879) reached me. Full justice is done to this admirable memoir at the end of the 
present paper. 
Almost from the moment of my arrival in Ceylon in the spring of 1880, my attention 
was attracted by the forms of Lichens so common on the upper surfaces of many leaves 
and flourishing in the warm damp atmosphere of that part of the island in which 
I resided for nearly two years. At such times as could be spared from other work, 
I endeavoured to form some idea of these organisms as a group, and slowly arrived at 
the conclusion that among numerous examples, provisionally regarded as different species, 
relations exist which compel one to consider many of them as stages in the development 
of a few forms. 
Few botanists, probably, would regard the accident of habitat of **Epiphyllous " 
Lichens as of more value than that of * Saxicolous," “ Corticolous” Lichens &c.; and 
I shall not, therefore, insist further on the more or less self-evident truth that no sharp 
line is to be drawn between these forms on this aecount. Nevertheless, while admitting 
that this is the case, it is not implied that the tropical Epiphyllous Lichens are neces- 
sarily to be distributed among known genera, a point only to be decided by research, 
and a matter of little importance to the purpose of this paper. 
Since it will be eventually shown, however, that all the facts of structure and develop- 
ment of the epiphyllous cryptogam immediately concerning us support the view that a 
Lichen is a compound organism, compounded of an Alga on which an ascomycetous 
Fungus has become more or less intimately affixed and dependent, it may be worth 
while to remove any superficial objections to classifying these organisms with other 
Lichens ; and this will be more thoroughly dealt with as we proceed. 
The organism to be described occurs on the upper surface of the leaves of so many 
plants widely separated in affinity and origin, that one must regard the species of the 
supporting plant as an accident. One general feature, however, is common to all these 
leaves: they are invariably hard and persistent, differing moreover in degree in this 
respect. I have specially observed this organism on the leaves of Coffea liberica, Ixora, 
SECOND SERIES.—BOTANY, VOL. ПГ. Q 
