Zeller: Development of Stropharia Ambigua 143 
annulus is early evanescent, but in most it persists to old age. It 
is difficult to keep dried specimens with the annulus intact. 
This species was reported as new by Peck (6) in 1898. The 
specimens from which the determination was made were sent by 
Dr. Lane from Portland, Oregon. Peck says, “ The dried speci- 
mens have the general appearance of some species of Stropharia, 
but the appendiculate character of the veil and the entire absence 
of an annulus indicate that the species is a Hypholoma.” Then, 
in 1912, Murrill (5), in summing up the species of Hypholoma 
of the Pacific Coast, says of this one : “ The species belongs 
naturally in Stropharia, but the large veil is entirely appendiculate 
and leaves no annulus.” Figure 12 is a photograph of a speci- 
men of my collection, No. 91, referred to by Murrill (5). The 
dried specimens of this collection which were sent to him for de- 
termination probably have no annulus intact. 
In the light of the present investigation there are two lines of 
differentiation between this species and Hypholoma, 
First, in the early states of Hypholoma, as worked out mor- 
phologically by Allen (1) and later verified by Beer (3), the dif- 
ferentiation of the parts does not correspond to that of this 
species. In Hypholoma the differentiation of the pileus preceded 
the other parts. Beer (3) also says that in Clitocybe laccata “ the 
first differentiation of the carpophore primordium consists in the 
demarcation of the pileus.” In Stropharia ambigua the first dif- 
ferentiation is the appearance of the primordium of the hymen- 
ium. Atkinson (2) found this true in Agaricus campestris, and 
Beer (3) observed the same order of development in Armillaria 
mellea. Thus, according to our present knowledge of the devel- 
opment of the carpophores of the Agaricaceae, with one excep- 
tion the annulate forms develop the hymenial primordium first, 
while other forms develop the primordium of the pileus first. 
Fischer’s work (4) on an annulate form may show an exception; 
but it seems to the writer that according to Fischer’s findings the 
differentiation of the hymenium brings about the differentiation 
of the pileus, and Beer (3) suggests that the differentiation of 
the pileus and hymenium in this case is possibly simultaneous. 
Further investigation on these two types has been started by the 
writer. 
