196 BOTANICAL GAZETTE [MARCH 
better understood, it will be found that in none of them, not even in 
the Helvellineae, is the hymenium exposed from the first.”’ 
- An obstacle to the ready solution of this and other details of 
ontogeny is, as Dirtricu has already pointed out, the difficulty of 
obtaining young stages either by collection or culture. BREFELD (3) 
made attempts to cultivate the spores of several Helvellineae, but 
though a mycelium was produced in some cases, no fruiting bodies 
could be obtained, and often germination did not take place at all. 
MOti1arp (16) had better success with spores of Morchella esculenta, 
from which he was able to procure a vigorous mycelial growth. 
This mycelium produced conidia identical with those of Costantinella, 
and when planted in a compost of apples gave rise to a couple of 
small fruiting bodies of the morel. 
In regard to the taxonomy of the Helvellineae various criteria 
have been adopted. SCHROETER’s (17) classification bases the dis- 
tinction between this group and the Pezizineae on the supposed 
gymnocarpous origin of the fruiting body in the former and the angio- 
carpous in the latter. Bouprer (2), in endeavoring to construct 
a natural classification of the Discomycetes, adopts a feature other 
than angiocarpy or gymnocarpy as a basis. He looks upon the Heb. 
vellineae as a polyphyletic group: one part, comprising the Hel- 
vellaceae and the Rhizinaceae, being placed in that division of the 
Discomycetes (Operculés) whose asci open by an apical cap; and 
the other, consisting of the Geoglossaceae, being relegated to a second 
division (Inoperculés) whose asci open merely by a pore. BREFELD 
found on examination of several Discomycetes that when an ascogo- 
nium is present the ascogenous hyphae appear quite early, but when the 
fertile filaments spring from ordinary hyphae, as he stated to be the 
case in several of the Helvellineae and some Pezizas, the ascogenous 
hyphae are differentiated at a much later stage. He thought that 
as the ascogonium occurs in simple forms but not in the more special- 
ized, and that as the specialized forms themselves differed, according 
to the species, in the time at which the ascogenous hyphae appeared, 
the gradually later and later differentiation of the fertile filaments 
would form a very good basis for the arrangement of the Discomycetes 
in a natural series, at the end of which the Helvellineae would prob- 
ably stand. 
