132 
F. Cavers. 
Spruce in Brazil, the vegetative portion of the plant consists of 
a branching thallus, closely resembling in appearance that of 
Metzgeria (Fig. 5). On either side of the cylindrical midrib there 
is a broad lamina consisting of a single layer of cells. Apical 
branching seldom or never occurs, but numerous branches arise 
ventrally from the sides of the midrib, and as each of these 
branches is joined to the main shoot only by a narrow base, it 
readily becomes detached and grows independently. The sexual 
organs are borne on ventral shoots which arise in the same manner 
as the sterile branches, but which bear well developed leaves in two 
lateral rows. The writer has, thanks to the kindness of Mr. M. B. 
Slater, F.L.S., Malton, had an opportunity of examining a large 
Fig. 5. Pteropsiella froiidiformis. Part of a male plant, showing above 
a male branch which has, after producing antheridial bracts grown out as a 
thalloid shoot; below are two branches, one flagellate and rhizoid-bearing 
the other antheridial; m., midrib; rh , rhizoids. x 10. 
number of plants from the Spruce collection, and can confirm the 
observations and conclusions of Goebel on the morphology of this 
genus. Goebel 1 states that in the material at his disposal, the 
growth of the male shoots had invaribly terminated on the develop¬ 
ment of the antheridia, but the writer has found in two cases that 
the male shoot had resumed its growth after producing the 
antheridia, the apex growing out to form a flattened branch, the 
margins of which bore the characteristic unicellular appendages 
(Fig. 5). 
In addition to the intercalary or adventive branches described 
in the preceding paragraphs, we occasionally find in the Acrogynae 
that adventive branches grow out from the leaf-cells or from the 
1 Goebel, K., Rudimentare Lebermoose. Flora, 1893, Heft 2; 
p. 91. 
