LEVINE: SPORADIC APPEARANCE OF NON-EDIBLE MUSHROOMS 59 
Panaeolus campanulatus L.,* which was the first member of 
this genus to be recognized as poisonous, also appeared in the 
mushroom beds. These plants appeared late, however, after the 
crop of Agaricus campestris mushroom was exhausted. The 
size and abundance of the sporophores might make them tempting 
to the uninitiated. The characteristics of the plants observed 
were identical with those already described for this species. The 
color of the pileus may be more accurately described as tilleul 
buff (Ridgw.) at the center and darker at the margin. 
Panaeolus retirugis Fr. (PLATE 2, FIGS. 9-11) was also found in © 
the beds mixed in with the sporophores of Agaricus campestris. 
It was the next most common to P. venenosus. A large number 
of these. plants were collected during the month of April and they 
had been fairly common earlier. Species of Panaeolust in general 
have been regarded as suspicious, especially P. retirugis. This 
plant was studied toxicologically by Ford and I have also found 
it to be poisonous to the same degree as P. venenosus when applied 
to the gastrocnemius muscle of the frog and the vagus nerves of 
frogs and turtles. The characters of the plant, as grown in dung- 
piles and well-manured lawns, are well known and the specimens 
collected by me were fairly typical. 
The occurrence of Panaeolus campanulatus and P. retirugis 
in the mushroom beds may be accounted for by the coprophilous 
nature of these plants. It is possible that the mycelium of these 
species of Panaeolus are brought into the mushroom houses with 
the manure or introduced by flying spores in early autumn. 
The other possibility lies in the method employed for obtaining 
commercial spawn. It appears that some of the spawn makers 
in the eastern United States are following the method employed 
in England and France for obtaining a commercial spawn.t 
This consists of making trenches in the sod, where “spontaneous” 
mycelium or sporophores of Agaricus campestris appear in the 
oe See ‘Mclivaine ; & Macadam. One thousand American Fungi 386. 1900 
See Krieger, C.C.L. Note on the reported poisonous properties of Copriwus 
comatus. Indiana. Mycologia 3: 200-202. 1911. Also Murrill,W.A. Anew poi- 
sonous mushroom. Mycologia 1: 211-214. 1909. 
tSee Duggar, B. M. The cultivation of the mushroom. U. S. Dept. Agric. 
Farmers’ Bull. 204; 1-25. 1911; The — * mushroom growing and mushroom 
spawn making. U.S. Dept. Agr. Bur. Plant Ind. Bull. 85: 1-60. pl. 1-7, 1905; 
Mushroom growing 92. New York. fore 


