410 BOTANICAL GAZETTE | JUNE 
This lichen does not form soredia. Other than the strictly 
vegetative mode of reproduction, which has been described in 
the foregoing, the only mode is by spores. The apothecia in 
which these are produced form on all older, though not necessarily 
oldest, parts. Either a very few comparatively large ones are 
produced on the flat, narrow strands forming the coarser nets, or 
a few still larger ones are scattered over the broad, usually short, 
plates, from which many branches spring, or finally a great num- 
ber of small ones arise on similar, but older, broad expanses. 
The apothecia usually form on the flat surface rather than on 
the edge of the thallus, thus exhibiting a tendency directly oppo- 
site to that of the branches ; but there are exceptions to both 
parts of this rule (fig. 7 ap. \F 
The origin of the holes in the thallus of this lichen has been 
discussed in several papers already. Of these I have been able 
to see only three, namely, Agardh’s original papers,‘ in which he 
first describes the plant as an alga, and Lutz’s.5 In the last,various 
papers are cited. After summarizing and criticising the views 
of his predecessors, Lutz proceeds to describe his own experi- 
ments and conclusions. He-worked only with dried herbarium 
material, and had never seen the plants in nature. His observa- 
tions were, therefore, necessarily limited, and his results are 
naturally incomplete. Indeed, the obscurity and uncertainty 
regarding this lichen are due to the unnatural conditions under 
which small quantities of it have been examined, from the time 
when Agardh acquired some of it, supposed it to be an — 
and named it “ Chlorodictyon foliosum (J. Ag. mscr.) Hab. 
in Hb. -J, E, Gray. (sine ulla de origine et loco OT 
until now, 
Lutz calls attention to the gelatinous material in which the 
outer hyphe are imbedded, and to the fact that, because of this, 
the outer parts at least will swell when moistened. He cut tet 
*(a) Chlorodictyon. Ofvers. af K. Vetensk. Akad. Férhandl. no. 5, 18793 - 
(4) Lund’s Univ. Arskr. 95 23. 1873, 
5Ueber die sogenannte Netzbildung bei Ramalina reticulata Krplhbr. 
Deutsch. Bot. Gesellsch. £22 7. 1804, 
5 Tid. a 34. 
16 
Ber. d. 
NS a ee ee a ee ee eT Se NS ee ae Le eee ee 
