440 BOTANICAL GAZETTE [DECEMBER 
that the proangiospermous or hemiangiospermous plant types 
which will exhibit critical developmental phases are likely to be 
inconspicuous, and that they must be studied with extreme care. 
Our hypothetical archaeosolandrous type, for instance, could be 
very easily missed, though found in excellent preservation. It will 
be necessary for that fortunate collector who finds the horizon and 
locality with lineal members of the early angiosperm line imbedded 
in it, to apply to his material all the newer laboratory methods, 
namely: (1) the staining, imbedding, and sectioning method used 
by JEFFREY and Ho ttick in dealing with forms apparently more 
like impressions or carbonaceous material than the partly preserved 
structures such as they finally found; (2) the developmental method, 
by means of which BEECHER showed the preservation of the most 
delicate trilobite structures, and won such clear results; (3) the 
collodion method of NatHorst for recovering microscopic surface 
details, which are often present. 
‘That intermediate types will be found in increasing number can- 
not be an idle prediction. That from tinie to time there will be found 
types definitely hypothesized, may be hopefully expected. Ten 
years ago I predicted the discovery of the seed ferns, now known in 
such number and variety. Even then it had become clear that 
“progressive prothallial elimination with correlated spore differentia- 
tion and alteration of the frondlike sporophytes of primitive ferns 
of the marattiaceous or an allied group were the basal factors in the 
evolution of the cycadofilicinean and cordaitean alliance.” And it 
already seemed probable that the angiosperms could be added in 
this statement. 
At the present time these groups seem to present more and more 
distinct points of contact, though in a very complex manner, oer 
ently calling into requisition nearly every thinkable modification of 
the monosporangiate and bisporangiate frond, both on the same and 
on separate axes, and with nearly every conceivable variety of os 
arrangement, reduction, sterilization, and suppression. Even m the 
Cycadales, the better known of which form a really compact group, 
we have been compelled to say that the orders “do not appear “ 
have passed through precisely the same. evolutionary sae tones . 
heterospory, bisporangiate or monosporangiate, monoecious, 42 
finally doecious fructification.” 
