Mar. 3,1923 
Origin of the Central and Ostiolar Cavities in Pycnidia 747 
inlPlate I, D, where there are no traces of the hyphalike branches; but 
the big cavity is filled with the stainable disorganized remains, suggesting 
very strongly that much of the nutrient for spore formation is obtained 
from within. In more mature pycnidia the central and ostiolar cavities 
will contain many spores, but no stainable cell remains (PI. 1, E). 
Sporophores are less easily distinguished in mature pycnidia because 
they are used up more and more as the food supply becomes exhausted 
in spore formation. This was pointed out by Bauke (2). It would be 
difficult to prove in any case, but it is not improbable that the entire 
layer of fertile cells bearing the first functioning sporophores may disap¬ 
pear and new sporophores, one by one, grow out from the cells next in 
line. The cavity certainly increases in size, and the extent of the ti ss ue 
lining it diminishes. Plate 1, D and E, shows an elliptical cavity in the 
necklike portion which serves as a temporary storage space for spores. 
SPERMOGONIA OP THE FUNGUS 
One finds statements regarding the transformation of spermogonia into 
pycnidia, or vice versa, or of either of these forms into perithecia. No 
one has given us the story of what happens to the pycnidia covering a 
Particular grape placed out of doors throughout the winter. After a 
somewhat extended study of this fungus, the writer is still unable to 
distinguish positively the bodies out of which spermogonia or pycnidia 
will be formed. He suspects that each of these spore-producing bodies 
arises from its own peculiar primordium, notwithstanding the fact that 
it is not at all rare to find pycnospores in spermogonia. 
As noted previously (p. 745), the perfect stage of PhyllosUdina carpogena 
remains in doubt. Further evidence that it may be a Guignardia is that 
it has a spermogonium very much like that of Guignardia bidwellii. 
Spermogonia and pycnidia may be found side by side on the dewberry, 
and were it not for their contents these fruit bodies could not be dis¬ 
tinguished. In size, shape, and wall structure they may be identical. 
In many spermogonia there is found the same peculiar elliptical ostiolar 
cavity (PI. x, F) so characteristic of pycnidia of this species. The writer 
has studied much more extensively the formation of the cavity in sper¬ 
mogonia of Guignardia bidwellii. The processes appear to be the same 
in both species. 
CAVITY FORMATION IN THE SPERMOGONIUM 
Cavity formation begins rather in the apical portion of the primordium 
of fundamental tissue where by partial disorganization of cells way is 
made for growth of orientation by which chains of cells become directed 
toward the apex. This stage, once initiated, is carried on very rapidly. 
Protospermatiophores which are long and threadlike soon fill the central 
Portion (PI. 1, F), each hypha (?) consisting of a chain of rodlike cells sur¬ 
rounded by a mucilaginous sheath. These cells, freed from each other, 
could scarcely be distinguished from spermatia; and it is possible they 
a re the first spermatia formed. Eater, when definite spermatiophores 
(Fig. 1, f.) can be clearly made out, the cavity is devoid of such thread- 
like aggregations, and very distinct rod-shaped spermatia lie around in 
the cavity. This suggests that the structures shown in Plate i, F and G, 
now break up and disorganize, leaving the mucilaginous products still in 
the cavity, and that definite spermatia will soon be formed. 
27134—23-6 
