confluent, and the Morphology of the Aseocarp . 393 
further come to germinate directly into ascogenous hyphae 
by a process of apogamy and the suppression of the ordinary 
mycelium and sexual organs. The condition would then 
be physiologically analogous to that in those Flowering Plants 
such as Allium and Funkia , as described by Strasburger, 
in which the nucellus-cells, which are potentially spores or 
spore mother-cells, bud out, push into the embryo-sac, and 
produce new sporophyte-embryos there in place of the fer¬ 
tilized egg which would normally be developed. 
Such suppression of stages in the development of an 
organism is shown in less degree by the cases of apospory 
in the Ferns, and the development of new garnetophytes from 
protonemata grown from the vegetative cells of the sporophyte 
in Mosses, as described by Pringsheim. On the supposition 
given, the condition in the Exoasci would be quite analogous 
to what is found in the Rusts according to Raciborski (29), 
who believes that the original vegetative body in these plants 
has been almost entirely suppressed, the present mycelium and 
spore-forms of the group being merely stages intercalated 
between two phases of the reproductive act, namely, cell- 
fusion and nuclear-fusion. If the fusions of cells and nuclei 
in the sexual apparatus, and the fusions of nuclei in the ascus 
should be found to be two phases of a single sexual act, the 
suppressed stage in the Exoasci on the view suggested above 
would be the same as that which Raciborski believes has 
been suppressed in the Uredineae. 
The Exoasci certainly give evidence of considerable speciali¬ 
zation in their parasitic habit and in their production of 
conidia in the ascus, and it seems quite as natural from 
this standpoint to regard them as a specialized offshoot from 
the main series of Ascomycetes as to regard them as primitive 
ancestral forms. The fact that their hymenia are without 
paraphyses is a minor point which agrees well with the 
hypothesis I have advanced above, since in the typical 
Ascomycetes paraphyses are outgrowths of the vegetative 
mycelia and not of the ascogenous hyphae. 
Whether or not this is the true explanation of the reduced 
