256 University of California Publications in Botany [Vol. 6 



hyphae immediately below the hymenium or surface of the stipe and 

 force their way up through the hyphae, or basidia as the case may be. 

 The glands are usually dark brown in color, or hyaline if empty. They 

 secrete or give off a milky juice which sometimes appears in drops at 

 the mouths of the tubes or on the stipe. Under the microscope the 

 liquid is seen to be made up of a fluid, colorless portion and numerous 

 globular particles, 1 to 2fx in diameter, resembling conidia in some 

 respects, but giving a red reaction with tincture of alkanna, indicat- 

 ing them to be of a resinous or oily nature. When this liquid dries 

 it becomes a dark brown. 



The stipe has a thin rind, 16 to 20jt(, in thickness, formed of the 

 swollen tips of hyphae curved outward so that they stand in a position 

 perpendicular to the surface. These swollen tips are 8 to 12/a in 

 diameter. Clusters of glands similar to those found in the tubes also 

 occur on the surface of the stipe. Some of these clusters are 280 to 

 350/x in diameter. The context of the stipe consists of hyphae 2 to 4ft 

 in diameter and lying nearly parallel to each other and to the long 

 axis of the stipe. 



Rostkovites granulatus (Eastern) 



A single dried specimen from the Eastern United States was con- 

 tributed by Dr. W. A. Murrill. Its morphological characters, so far as 

 could be determined from dried material, agreed in every respect with 

 our Californian plants referred to this species. An examination of 

 the histology of this plant was made for purposes of comparison with 

 the histology of our Californian species. 



Histology 



The surface of the pileus is but very slightly differentiated. The 

 hyphae are somewhat more densely intertwined and darker in color 

 than are the hyphae of the context, but there is absolutely nothing like 

 the long hairs found in the Californian plants referred to this species. 

 The hyphae of both the surface and of the context of the pileus are 

 3 to 4/x in diameter (pi. 25, fig. 32). 



The structure of the hymenium is the same in every respect as in 

 that of the Californian form, except that the glands are less abundant. 



The surface of the stipe is covered by a definite rind 50 to 60/t in 

 thickness. The outer layer of this rind is formed of club-shaped, 



