AND LIFE-HISTORY OF A TROPICAL EPIPHYLLOUS LICHEN. 119 
Fig. 62. Portion of Lichen after the Fungus has completely invested the Alga and has formed several 
pycnidia. The sea-green tint is due to the green colour of the Algal cells shining through the 
masses of hyphæ ; the cuticle is observed at the edges, and the faintly marked radial shading 
follows from the mode of growth &с. Gundlach 4. 
Fig. 63. A separated pycnidium, with its immediate mycelium and apical pore. Zeiss E. 
= 64. Vertical section of the Lichen-thallus, passing through two pyenids. One is cut in the median 
plane, and stylospores are escaping through the apical pore ; the other is cut much on one side, 
and the felted walls are exposed. Passing from the pycnidia are interwoven hyph:ze, which avs 
raised up the Alga (the cells of which contain green and red pigment) and formed a dense 
cushion of air-containing tissue between it and the epidermis of the leaf. Over the Alga is a 
distinct cuticle. Zeiss D, oc. 4. 
Fig. 64 a. Stylospores in various stages of development. Zeiss J. 
Fig. 65. Vertical section through the Lichen-thallus and part of a pyenid, with young stylospores deve- 
loping оп its walls. Тһе Alga, as before, upraised by dense feltwork of hyphe containing air 
in the interstices. Zeiss Е. 
Fig. 66. Vertical section through the perithecium and thallus of the Lichen. Asci and paraphyses 
radiate inwards from the wall of the perithecium ; aud the spores escape through an apical роге; 
other details much as above. Zeiss D, oc. 4. 
Fig. 67. Germinating spores of the Lichen. Zeiss J. 
Fig. 68. Asci and spores from the perithecium, mingled with paraphyses (а & b). At d the swelling 
and introversion of the lining of the ascus is shown: a, Zeiss D; 6, E; c & d, imm. yy. 
Figs. 69 & 70. Very thin vertical sections of the Lichen-thallus, highly magnified (Zeiss L immersion) ; 
showing details of the hyphal network among the rhizoids of the Alga; the cells of the latter 
still retain their green and orange pigment, and a distinct cuticle (displaced in fig. 70) 
covers all. In fig. 70 are seen transverse sections of three hyphz above : cf. also fig. 65. 
SECOND SERIES.—BOTANY, VOL. П. U 
