8 BOTANICAL GAZETTE [JANUARY 
lie around the stem a short distance below the margin of the pileus 
in the form of a ring (fig. 1). It is so delicate that it collapses, 
dries, and disappears very soon after the expansion of the plant, 
or is washed away by the rains, so that it is probably rarely seen 
except by those who collect the mature “eggs,’”’ and in a protected 
place observe the unfolding of the plant. 
The delicate and evanescent character of this “veil” may 
account for the fact that it is rarely shown in connection with illus- 
trations of this species after expansion, especially in works of a 
general character. This has probably led to the rather wide- 
spread belief, especially in some quarters, that a “‘veil’”’ is want- 
ing in Ithyphallus impudicus. The variability in the strength of 
this ‘‘veil” in individuals of the same species, and in different 
species, as well as the presence of the indusium in Dictyophora, 
occupying a similar position between the pileus and stem, though 
of a different structure and ontogenetic history, has led to con- 
siderable confusion regarding its nature, origin, and taxonomic 
value. Many writers have used the terms ‘‘veil’’ and ‘‘indusium” 
synonymously. If the word velum or ‘‘veil’’ were used to desig- 
nate the remnant of primordial or fundamental tissue lying at 
maturity of the plant between the pileus and stem, and if the 
word indusium were reserved for the organ of different structure 
which is differentiated and developed from a portion of and within 
this primordial tissue, it should serve to clear away the existing 
confusion. A comparison of these structures and a consideration 
of their origin and later history in [thyphallus impudicus, Dictyo- 
phora duplicata, and Phallus ravenelii, with photographs of stained 
sections, together with a discussion of some of the literature of the 
subject, it is hoped will lead to a more intelligent understanding 
of their nature and taxonomic significance than can be obtained 
from an examination of them at the time of the expansion of the 
plants. 
Ithyphallus impudicus is a rare plant in the northeastern part 
of the United States. I have never seen a specimen from this 
region. Dictyophora duplicata is rather common, however. Its 
size and form, as well as the surface of its pileus, are so similar to 
I. impudicus that, as Burt (1b, p. 384) remarks, there is danger 
