THE DEVELOPMENT OF THE CARPO- 
PHORES OF CERIOMYCES ZELLERI 
Sanford M. Zeller 
(With Plates 140 and 141, Containing 12 Figures) 
A review of the literature shows that very little, if any, critical 
research has been done on the development of the carpophores of 
the fleshy pore-bearing hymenomycetes. Among the early writers, 
DeBary 1 mentions some of these when he divides the carpophores 
of hymenomycetes into two groups; viz., angiocarpic, or those 
forms having a marginal veil, and gymnocarpic, those forms “of 
purely marginal or apical progressive growth ” and thus, of course, 
without a marginal veil. He says that Boletus luteus and B. ele- 
gans have marginal veils, while other species of this and other 
genera are purely gymnocarpic. Thus, with these few exceptions, 
he merely assigned Boletus to the gymnocarpic type of the de- 
velopment without a critical study of the genus. A study of the 
development of a species of Boletus was undertaken because it 
promised to throw some light upon the types of devlopment of the 
pileate fungi. Material for this study was collected in the fall of 
1912. Ceriomyces Zelleri was chosen because it is so very com- 
mon about Seattle, and because its gregarious habit facilitates the 
collection of sporophores in the young stages. 
The material for the study of this species was collected in a 
forest of conifers on the campus of the University of Washington. 
It was in this place that the type specimens 2 were collected. There- 
fore, the identity of the species is certain. 
The young fruiting bodies were found in quantities growing 
from a yellow mycelium which causes a matting of the conifer 
needles. Sections of the rhizomorphs which lead to the carpo- 
1 DeBary, A.: Comparative Morphology and Biology of the Fungi, Myce- 
tozoa and Bacteria. English Edition. 289-297. 1887. 
2 Murrill, W. A.: Pacific Coast Polyporaceae and Boletaceae. Mycologia 
4: 99-100. 1912. 
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