[ilCRi ISCOPIC < ll kfl U / / RS 27 



smoother appearance, especiall) when faded, than the pileus of 

 Type 1. A great deal ol Lntergradatioii occurs between these two types 

 so that at times it is difficult to decide which category fits the best. 



Type 3. The ixocutis ( Fig. It), a I : This t\ pe is .i progression From 

 the previously described cutis in which the hyphal walls show ili.it the) 

 are chemically different From the walls of the context hyphae b) swell 

 ing up and gelatinizing in water or KOI I. The gelatinized material 

 gives a translucence to the layer which is in quite sharp contrast to 

 the context. Gelatinized hyphae have a tendency to he onlj L.5 3 << in 

 diameter, and the whole layer has considerable tenacity, For it can Fre 

 (jiientlv be peeled From the cap as a film. This is what is me, ml b\ 

 a separable pellicle which common!) occurs in section Hygrocybe. In 

 some species the layer can be 50 fi or more thick and in others onl) 

 10-15 fx or even less. Tin 4 extent to which gelatinization occurs deter- 

 mines how Sticky or slimy the fresh pileus is when tone lied. Examples 

 are found in H. agathosmus, odoratus, and rainierensis | Fig. LO 



Type 4. Trichodermium (Fig. 8): This is a totally different type 

 from any of the first three 1 . In a trichodermium the context hyphae or 

 branches from them project upward or more or less perpendicular to 

 the surface and become aggregated into small bundles, which to the 

 naked eye appear as minute squamules. These projecting hyphae 

 may be two- to several- or more-celled with the terminal cell at times 

 somewhat cystidioid in shape-, and the walls are not gelatinous. s 

 eral examples of this type are found in Hygrocybe, scries Hygrocybe 

 (H. miniatus, Fig. 8, e; H. turundus, etc-.). A somewhat special type 

 is represented by //. rugulosus. In it the 1 cutis is a trichodermium in 

 which the elements all terminate at the same level to produce 1 an h\ - 

 meniform epieutis of pedicellate-inflated to vesiculose elements. \\ < 

 believe that the epieutis in the species of section Hygrotrama origi- 

 nated by a shortening of the trichodennial hyphae to a point where 

 these consisted of simply an apical cell with a single 1 modified penulti- 

 mate cell. 



Type 5. The ixotrichodermium ( Fig. 9): In many Hygrophori the 1 

 epieutis of the pileus consists of a trichodermium of very narrow- 

 branched hyphae (1-3 \> diameter) covering the 1 pileus surface like a 

 turf, and are imbodele'el in a mass of slime 1 . Such a surface 1 is very 

 slimy when fresh and wet. and has a varnished appearance when dry. 

 This type e>f epieutis ma\ not be 1 as readily separable as in Type 3, 

 From this it is evident that viscidit) of the pileus is based on two dif- 

 ferent anatomical types of epicuticular structure. Actually, from the 1 

 standpoint of the 1 shape of the epicuticular elements two subtypes can 

 be recognized in Type 5: (1) one in which the 1 hyphae stand erect. 



