62 PROCEEDINGS OP THE AMERICAN ACADEMY. 



chambers are in free communication with the air, is shown, considerably 

 enlarged, in fig. 11. The peridium, which thus encloses the gleba often 

 more or less incompletely, is further continuous with the columella where 

 it emerges at the apex (fig. 10) and also below with the stipe. 



In the interior of a typical specimen, the columella, which is a direct 

 continuation of the stipe, runs to the apex and is externally visible, 

 either as a more or less orbicular depression or a slight elevation. 

 Though this is usually at the apex of the body, it is sometimes a little at 

 one side (fig. 5). The firm sub-gelatinous axis consists of branching 

 hyphae closely interwoven, and running more or less parallel. From 

 the columella proceed the tramal hyphae toward the peridium. In a 

 section of a mature specimen the tramal plates appear to branch and 

 anastomose so as to form closed chambers, while from the trama arise 

 many hyphae which bear basidia in groups (figs. 14, 15). The basidia, 

 growing at right angles to the trama, form, as usual, the hymenial layer 

 which lines the chambers (z', fig. 7). The gleba (z) is thus formed be- 

 tween the peridium (x) and the columella (y), and consists of a series of 

 chambers which appear to be more or less continuous with one another, 

 and are lined with typical 4-spored basidia. The spores are brown, 

 smooth, ovate to elliptical, borne on well-developed sterigmata, and with- 

 out any distinguishing peculiarities. Usually each basidium (fig. 15) 

 has at least a basal septum, and in some cases there are also indications 

 of one more or less median septum. 



Development. 



Alcoholic material was used in studying the young stages. About a 

 dozen specimens, ranging from 3 mm. to 8 mm. in height, were imbedded 

 in paraffin, and cut into sections 10 n thick. For staining, Haematoxylin, 

 Safranin, and Bismark Brown, were employed, the Haematoxylin 

 giving better results than the two others. Dried material soaked in 

 potassium hydrate and picked apart under a dissecting microscope, 

 showed the groups of basidia, their form and septation, very clearly. 



The youngest specimens examined, which were merely pointed up- 

 growths from the running mycelium, showed no indication of differentia- 

 tion. In a specimen 3 mm. long, for example, there is no differentiation 

 of gleba, but simply a loose interweaving of superficial hyphae which is 

 the first indication of a peridial layer. There is also in these specimens, 

 at their apex, a sheaf-like spreading of the parallel hyphae, which is very 

 marked in the older ones (figs. 8 and 9). 



