DEVELOPMENT OF EXOGENOUS SPECIES OF AGARICS 
37 
to his rather indefinite Hmitations of the "couche pileogene" and the 
"primordial cuticle," and also to the fact that he considered all the 
forms to arise endogenously, there is considerable need for reinvesti- 
gating these forms. 
The excellent work of Blizzard (9) in 191 7 has confirmed, in the 
case of certain species of Omphalia, Clitopilus and Clitocyhe, the final 
conclusion of DeBary and Hoffmann. This present paper is offered 
as a further contribution to our knowledge of the exogenous forms. 
Mycena suBALCALiNA Atkinson.* 
(Figs. 1-24) 
One of the autumnal species of fungi, which is found frequently 
in great abundance in the woods about Ithaca, N. Y., is Mycena 
suhalcalina. It is a small mushroom, rarely exceeding 2 cm. in the 
diameter of its pileus. On account, however, of the profusion in 
which it grows on decayed stumps and the ease with which it may be 
collected free from soil particles, it lends itself very readily to morpho- 
logical study. 
Collection and Preparatio?i of Material. — The material for this 
study was collected at two different times, once on November 7, 1914, 
from the marsh at McLean, N. Y., and again on January 20, 1915, 
from the inside of a hollow trunk in the Beech Woods by Six Mile 
Creek near Ithaca, N. Y. At this time the ground was covered with 
snow and the fruit bodies, which were exposed on the surface, were 
covered with a coating of ice, apparently interrupted in their develop- 
ment by the coming on of winter. Some of these latter, together with 
others from the interior which were not frozen, were immediately 
fixed in medium chromo-acetic acid. All of the material proved 
* Mycena subalcalina Atkinson, n. sp. Caespitosa vel subcaespitosa, 3-7 cm. 
alta; pileo convexo dein expanse, avellaneo-brunneo vel castaneo-brunneo, 1-2 cm. 
lato, leniter striate, lento, humecto sed non viscido; lamellis albis demum sub - 
sordidis, angustatis, subdistantibus, arcuatis, adnatis, dente decurrentibus; cystidiis 
nullis vel raris, ad aciem lamellarum clavatis, non emergentibus, frequenter mucron- 
atis; sporis quaternis, levibus, subellipsoideis vel ovalibus, minutissimis, 3-6 X 2-2.5 /z; 
stipite sursum albo vel pallido, deorsum luteo-rufescenti, ad basem atrobrunneo et 
strigoso, apice leniter pruinoso, 2-3 mm. crasso. 
On decaying wood in the vicinity of Ithaca, N. Y, The plants are tough and 
pliant when fresh, with an alcaline or nitrous odor, though sometimes faint. 
