1^16] Yates: Histology of Calif ornmn Bolefaceae 245 



and do not change color. The mouths are circidar and very small 

 (4 to 5 to a mm.). The spores are slightly more elongated. The 

 surface of the stipe is nearly white, roiig-hened but never reticulate. 

 All parts of the plants tui-n blue where attacked by insects. 



Emphasis should be plaetnl upon the fact that a well-devoloped 

 and fairly thick veil is present in young' individuals referred to this 

 form. This veil can be seen in plants up to 1.0 to 1.5 cm. in length 

 but disappears later, leaving no trace either upon the stipe or upon 

 the margin of the pileus. 



Specimens of this form of Ceriomyces crassus are filed in the 

 herbarium of the University of California under the following num- 

 bers: Xo. 33 collected at Brookdale in the Santa Cruz Mountains, 

 and No. 72 collected near Muir Woods, INIarin County. Material 

 showing the presence of the veil in the button state is preserved in 

 alcohol under No. 72. 



Histology 



Upon examination under the microscope the surface of the pileus 

 is seen to be covered to a depth of 200 to 220/i, with a felt of reddish- 

 ])i-own liairs. These hairs are 4 to 8/i, in diameter and have occasional 

 septa. Tliey contain a reddish-brown substance which is found in 

 greatest abundance near the tips of the hairs. These hairs are em- 

 bedded in a brownish .jelly to form a rather compact cuticle or rind. 

 Beneath this rind is the context, composed of tangled or felted hyaline 

 hyphae 4 to 8/a in diameter (pi. 24, tig. 21). 



The hymenium is made up of basidia and paraphyses only, no 

 cystidia having been observed in these plants. The basidia project 1 or 

 2/i above the paraphyses. The subhymenial tissue is formed of hyphae 

 2 to -i/x in diameter, which contain a granular material and which 

 are 1)ut little interwined. At the center of the tissues between each 

 foui- tubes we find a darker mass of hyphae. These hyphae are 

 2 to 4/( in diameter and filled with a densely granulai- substance. 

 The hyphae are woven very closely together to form a dense and 

 rather opaque mass. 



Tlie sni-face of the stipe is covered with a dense yellowish-l)rown 

 rind .")() t(t (lO/x in thiclcness made up of densely compacted hyphae 

 2 to -i/i ill diameter. The context of the stipe consists of hyphae 

 4 to Sfj. in diameter Avhich are very much branched and ct-owded 

 together. The hyphae forming the context of the stipe are neai-]\- 

 hyaline and contain verv little uranular material. 



