ATKINSON: LEPIOTA CRISTATA AND L. SEMINUDA 215 



the apex of the primordial basidiocarp, i. e., parallel with the axis 

 of the stem. They are radial or perpendicular to the upper and 

 lateral surface of the young pileus primordium after its appear- 

 ance. While the general direction is radial, the hyphae are more 

 or less flexuousi and somewhat interwoven. This tissue is loose, 

 since there are rather conspicuous interhyphal spaces. Lateral 

 to the stem fundament the hyphae of the blematogen are nearly 

 or quite parallel to the stem axis, i. e., they are not radial, or 

 perpendicular to the surface of the basidiocarp, while they are 

 radial or perpendicular over the pileus fundament. 



As the fruit bodies become older the blematogen becomes 



more definitely organized into a compact palisade layer of hyphae 



over the pileus and extending a short distance below the margm. 



Lower down on the surface of the stem the hyphae remain nearly 



or quite parallel with the stem surface. In figures 3 and 5 the 



more compact nature of the blematogen layer is manifest. It is 



still better shown in figures 7-14 and in figure 17. Here it 



forms a distinct layer which can be seen to extend some distance 



below the margin of the pileus, but is not so distinct far down 



over the stem as it is in Lepiota dypeolaria (see Atkinson, '14). 



The radial character of the outer portion of the blematogen is 



well shown in figure 17. These radial hyphae are 5-10 M m 



diameter and 30-40 M long, but in mature specimens the dimensions 



are greater. These radial hyphae spring from a thin zone of 



pseudoparenchyma, similar to that in Lepiota dypeolaria {loc. ctL), 



but not so well marked. 



As the pileus primordium increases in growth it becomes 

 firmly united with the inner zone of the blematogen, so that the 

 latter becomes concrete with the surface of the pileus, and the 

 outer surface of the blematogen becomes the surface or "cuticle, 

 of the mature pileus as usually understood. 



The marginal or partial veil— The marginal, or partial, veil, 

 as in species of Agaricus, Lepiota dypeolaria and Armillaria mellea 

 described by the writer ('14, '15) consists partly of a section of 

 the blematogen, and partly of ground tissue extending between 

 the margin of the pileus primordium and the stem, the ground 



1 For a discussion of the blematogen and its relation to the volva in Amanita and 

 Amanitopsis, and to the universal veil in Lepiota clypeolana, and certain species ot 

 Agaricus, see Atkinson, '14 and '15. 



