2 72 Bower. — Some Normal and Abnormal 
forming plentiful chlorophyll ; others assume a brown colour, 
and, either with or without further branching, perform the 
function of rhizoids. The whole prothallus thus forms a 
much-branched matted growth, rising to a height of about 
a quarter of an inch. In its general aspect it appears to the 
naked eye not unlike a stiff-growing Vaucheria , and its fila- 
ments under a low power resemble a Cladophora. I have 
never seen the filaments of this species widen out into flattened 
expansions like those of Trichomanes alatum , to be described 
below, or of Tr. sinuosum and others described by Mettenius. 
In point of the filamentous form, the localisation of growth 
near the apex of the filament, the absence of intercalary 
growth, and in the branching not being restricted to one 
plane, as well as in the absence of flattened expansions, the 
protonema of Tr. pyxidiferum corresponds to the description 
given by Goebel for Tr. diffusum , Bl. and Tr. maximum. 
These species differ, however, from Tr. sinuosum as described 
by Mettenius 1 and Tr. alatum , as I shall show later, for in 
them flattened expansions of considerable size are commonly 
to be seen. 
Special interest attaches to the position of the rhizoids 
relatively to the filaments which bear them. They are in most 
cases clearly lateral, and correspond in position to the other 
lateral branches of the protonema ; finely-graduated inter- 
mediate steps, however, may be found from the lateral to the 
terminal position (Fig. 7, a-d), thus illustrating how members 
usually lateral may under circumstances undergo a gradual 
displacement so as to assume a position actually on the apex 
of the member which bears them. This observation has its 
bearing upon the question of the possible terminal leaf. 
Apospory . — On old fronds a dense tuft of such protonernal 
prothalli as those above described may be seen projecting from 
the cup of the sorus ; and as the germination of the spores is 
known to occur in the cup, or even in the sporangium itself, 
this might be considered a sufficient explanation. But if 
> lx. Taf. V. 
