Developments of the Oophyte in Trichomanes . 29 r 
(Fig. 34), but usually terminal (Figs. 35 > 3b). Thus, there is 
irregularity in this species with regard to the position of 
the flattened growths: this is again a character involved in 
Goebel’s scheme. 
Thus two of the characters cited in Goebel’s phylogenetic 
sketch are variable, not only in the genus or species, but 
even on specimens derived respectively from the same indi- 
vidual parents. I apprehend that the value of characters 
for phylogenetic argument is in proportion to their constancy 
of occurrence ; and accordingly these vegetative characters 
of the oophyte, which vary in different specimens derived 
from the same parent, or even in the individual specimen, 
cannot be considered as a sound basis for phylogenetic 
argument. 
Now, it is impossible to deny that in our views of the 
relationships of the Vascular Cryptogams much greater im- 
portance has usually been attached to the characters of the 
sporophyte than to those of the oophyte, and botanists will 
welcome an attempt such as that of Goebel to place the com- 
parison of the oophyte on a wider basis of detail. As a specu- 
lation on the course of evolution of the oophyte of the Ferns, 
Goebel’s scheme may be accepted as, on the whole, a probable 
one ; but the real question is whether any, and if so, which 
of the forms we now see living directly illustrate the original 
progression. Are they the result of degeneration, or may 
they not be immediately influenced in their development 
by present external conditions? I venture to think that in 
the comparative treatment of the oophyte of the Vascular 
Cryptogams even greater caution will be necessary than in 
that of the sporophyte, inasmuch as we have to deal here 
with a generation which we have every reason to believe is 
in its decadence, and is accordingly more subject to degrada- 
tion and its consequent modifications, than the sporophyte, 
which is seen, so to speak, in the nascent condition in the 
Vascular Cryptogams. And, as in the Phanerogams we may, 
under peculiar circumstances, see the vegetative organs re- 
duced both in internal and external complexity, so, though 
