32 NORTH AMERICAN SORDARIACEAE 
the function of spore dissemination ; but its behavior during this 
process is not known and the actual exit of spores from the ascus has 
never been observed. Zopf * was the first to describe this structure 
which is found in the apex of the ascus, and is easily recognized 
by its giving the characteristic starch-blue reaction withiodine. It 
possesses a definite structure and differs more or less in outline in 
the different species. It occurs in no other genus of this family, 
but according to my observations is very common if not constant in 
several of the genera of the Xylariaceae. Poronia, Xylaria, and 
Daldinia may be especially mentioned. 
It appears to be in organic connection with the protoplasm of 
‘the ascus upon which it rests and by which its base is more or less 
surrounded by short blunt processes. Its upper portion shades off 
gradually into the ascus wall from which it is separated by a very 
indistinct line of demarkation. Laterally in several species it is 
prolonged into long indistinct horn-like processes which project 
downward. When the ascus is viewed endwise the structure is 
seen not to be solid, but appears as a thick ring, bounded ex- 
ternally by the ascus wall. The whole structure is brought out 
very clearly by the application of iodine which gives to it a typical 
starch-blue color. Occasionally in Æ. equorum the reaction with 
iodine has been observed to be brown in many of the asci. But 
the brown is a very different color from the protoplasmic brown اہ‎ 
the remainder of the ascus. It should be described as more of a 
transparent umber. In A. merdaria faint striations may be seen 
in a lateral view, which are more readily seen when the color is 
being gradually extracted in dilute glycerine. It stains most 
deeply at the base and gradually fades out toward the apex and 
toward the lateral horn-like projections which are not colored at 
all except at their very bases. Zopf has given colored drawings 
of this structure as seen under the iodine reaction, but the definite 
shape and outline appears to have escaped him although he repre- 
sents perfectly the upward projections of the general protoplasmic 
contents of the ascus. This body appears before there is any sign 
of spores in the ascus and grows in size as the ascus and spores 
develop, but it is a perfectly definite structure from its first appear- 
. ance. 
* Zeitschrift gesammt. Naturwissensch. (Halle), 56: 1883. 
