416 Wisconsin Academy of Sciences , Arts , and Letters . 
the stem. In most cases the expansion of the pileus which fol¬ 
lows splits the veil and the fragments remain hanging to the 
margin of the pileus. Compare pi. XXIII E. with vol. XVII, 
pi. LXXX D and LXXXII E. In these annulate plants the 
veil is torn from the margin of the pileus without breaking 
up, and remains as a free annulus on the stem, pi. XXIII A 
and G. At the apex of the stem the veil remains attached to 
the edges of the gills and tears away from the stem leaving the 
gills joined together at their bases, pi. XXIII A. The part 
of the veil above the annulus is often broken into fragments 
by the elongation of the stem, leaving the stem furfuraceous 
or floccose above the annulus as in pi. XXII B. By this pro¬ 
cess the ridges on the veil are more or less obliterated. This 
breaking up of the partial veil above the annulus is analo¬ 
gous to that which takes place when the universal veil is 
torn into scales by the elongation of the stem in the volvar 
area in plants which have a volvar stem. 
c. A well developed cortex is formed on the pileus beneath 
the universal veil. The coating on the stem is less developed. 
The stem is hollow and the cavity is coated by a medullary 
sheath, pi. XXIII C. The context of the pileus becomes 
pithy in the center and is divided into a cortical and a sub- 
hymenial layer. It is the cortical layer which cracks and 
peels off in the forms like Hypholoma cutifractum, vol. XVII, 
pi. LXXXII. There is a tendency to crack in this manner in 
the pilei of all the forms in the group which I have observed. 
The split often begins at the apex of the pileus as in pi. XXIII 
G. The hollow of the stem extends into the pileus and the 
cortical layer becomes very thin at the apex of the pileus. It 
is often perforated as was noted in the descriptions of Hypho¬ 
loma candolleanum and Hypholoma longpipes. Plate XXIII 
D shows the apex of the pileus of the annulate form. The cor¬ 
tical layer has split off and the end of the hollow stem covered 
with the medullary sheath is seen in the center. Around it 
appears the dark subhymenial layer which connects with the 
growing tissue of the stem. The latter appears dark in the 
cross section of the stem, G, between the light tissue of the 
partial veil and the medullary sheath. In D the subhy¬ 
menial layer appears radiating outward under the gill 
chambers. The rays are divided by the lighter colored tissue 
of the trama of the gills. Plate XXIII G shows a cross section 
