(7// \li( \l (II \li \( 1 1 BS 



body. We have found that in section Hygrophorus the) are almost al- 

 ways present I bui are absent in //. adiaphonu , In CamarophyUopsis, 

 Hygrocybe, and Hygrotrama the) arc Frequent!) absent. We have do! 

 found them in //. foetens, II. hymenocephalus, II rugulosus, II nib- 

 fuscescens, 11. fallax, II. paupertinus, and //. peckianus. 



Jn Hygrocybe they are absent in a Dumber <>! sp i i< - II dt < i p- 

 tivus, II. marginatus, II. atro-olivaceus, etc. In some species we found 

 them present but very difficull to locate, as in //. immutabilis, II 

 caespitosus, 11. acinus, II. subovinus, and //. perplexus. In other sp 

 we found them restricted to the subh) menium onlj . //. calyptraeformis; 

 rare on cuticnlar hyphae, common on the stipe. //. miniatus var. longi- 

 pes; pileus trama only. //. turundus var. sphagnophilus; on laticiferous 

 hyphae only, //. firmus var. militaris and //. wt rftt. 



Our studies have convinced us that in Hygrophorus the presence or 

 absence of clamps on the hyphae ol the fruiting bod) is .1 good addi- 

 tional character to aid in delimiting species, but that it is extremel) 

 impracticable for the most part because of the irregular pattern of oc- 

 currence. We found ourselves differing as to whether clamps were ab- 

 sent in a number of species, and the answer too often turned out to be 

 that if vou look long enough you can find them. They seem to have 

 dropped out of the genus here and there without regard to relation- 

 ships of the species. Consequently we have de-emphasized their use in 

 our classification even though previously we (1954) published a ke) 

 to Hygrophori lacking them. The pattern of the occurrence of damp 

 connections in Hygrophorus is no different from that in most other 

 genera. The proportion of clamped to clampless species varies greatly 

 between genera. Critical studies on clamp connections based on ex- 

 periments with appropriate material and by means of cultures 

 should be undertaken. We do not really know what the absence oi 

 clamp connections on the hyphae of a fruiting body means in terms of 

 nuclear behavior. It would also be interesting to know whether the 

 mycelia which produce the clampless fruiting bodies have clamped 

 hyphae. 



CHEMICAL CHARACTERS 



The use of chemical characters in the delimitation of species is 

 nothing new. They have always been used as far as certain categories 

 are concerned, such as odor and taste, different pigments, etc., but the 

 features which have come 1 into prominence in the last two decades 

 mainly involve color reactions from the application ot specific reagents, 

 such as potassium hydroxide, ferrous or ferric sulphate, Mol/er's rea- 

 gent ( see Singer, 1951 ) . 



