354 
MICHAEL LEVINE 
The significance of this structure is not clear, although it may be the 
point of origin of secondary growth in the pileus as suggested by Miss 
Allen (1906). 
Summary 
1. The carpophore primordium of Coprinus micaceus arises from 
the mycelium directly or from a rhizomorph. The young button 
makes its appearance from forty to sixty days after either cornmeal 
agar or soil media are inoculated with spores. 
2. The pileus initial appears as a hemispherical mass of fine, 
narrow, interlacing septate hyphae having a dense cytoplasm which 
stains heavily with Flemming's triple. The peripheral layer of cells 
of the carpophore primordium is differentiated very early in that they 
stain more deeply. 
3. The primordium of the hymenium arises at or near the lower 
surface of the pileus primordium and appears in vertical section as 
two densely stained areas of palisade cells, symmetrically placed to 
the left and right above the center of the carpophore primordium. 
4. A palisade of hyphal cells is formed pointing obliquely downward 
so as to form a series of arched ridges. These ridges form the young 
gills. The hymenial elements do not enclose the edge of a gill but 
enclose the notch between two gills. 
5. The small opening formed at the point where the first formed 
palisade cells meet is the beginning of a gill chamber. The further 
development of palisade cells leads to the enlargement and further 
development of the gill chamber. 
6. Longitudinal tangential sections show the gill chambers in 
series, one gill chamber between each pair of lamellae. The hyphae 
of the trama of each gill run straight through into the stipe below 
and the pileus above. 
I wish to express my deep appreciation to Professor R. A. Harper 
for his many helpful suggestions. I also wish to thank Professor 
W. G. Marquette for his assistance in making the microphotographs. 
Columbia University, 
New York City. 
LITERATURE 
1906. Allen, C. L. The Development of Some Species of Hypholoma. Ann. Myc. 
4: 387-394. 
1906. Atkinson, G. F. The Development of Agaricus campestris. Bot. Gaz. 42: 
241-264. 
