MICROSCOPIC CHARAC1 I RS IS 



cur in the hymenium, and two distinct ranges <»l spore size arc Found, 

 the small spores coming from small basidia and the Large ones from 

 large basidia. A cytological stud) of //. Junius to count chromosome 

 numbers in the nuclei of each size of basidium might be most revealing. 



This phenomenon is also known as the Ascomycetes | ECanouse, 

 1950). It is not to be confused with the production of occasional «^iant 

 spores from occasional large basidia. a Feature of in;m\ agarics. In the 

 latter instances because so few spores arc produced they are not taken 

 into account in determining the size range. Occasional exceptionally 

 small spores may also be found in deposits. The most commonly occur- 

 ring situation which confuses the determination of spore size in Hygro- 

 phorus is the presence of 1-, 2-, 3- and 4-spored basidia in the hyme- 

 nium of a single cap. The presence of just 2-spored and 4-spored 

 basidia will produce a spore deposit giving spores which fall rather 

 neatly into a bimodal curve as far as size is concerned, but the pic tint 

 becomes very confused when all tvpes are present. It seems to us that 

 a more careful cvtological study of this genus than any yet made might 

 yield additional data of taxonomic importance. It is concluded that 

 basically spore size is a constant and valuable aid in the definition of 

 species in Hygrophorus, but that there are a number of factors which 

 must be taken into account in its use. 



Spore shape is rather monotonous in this genus, most spores being 

 elliptic to oblong or globose. However, a few species have fusoid spores, 

 and in a few others the spores in profile may be slightly curved. In a 

 few species the spores are extremely narrow, and in others peanut- 

 shaped (constricted in the middle). In H. sphaerosporus and H. hij- 

 menocephalus, with globose spores, there is a tendency for the spores 

 to have one side flattened and hence appear obscurely angular under 

 the microscope. 



In his studies Bataille (1948) reports the spores of most species to 

 be smooth. In a few, however, he finds them rough. According to him 

 the spore wall is punctate in H. caprinus (H. camarophyllus) , II. dis- 

 coideus, H. limacinus, H. marzuolus, H. olivaceoalbus, II. pudorinus, 

 and H. russocoriaceus. In H. agathosmus and i7. pratensis he described 

 them as subsmooth. We have found those in the above group occurring 

 in North America to have smooth spores. Morten Lange ( 1954), Moser 

 (1955), and Orton (1960) state that the spore wall in //. schulzeri is 

 minutely punctate-warty. Dennis (1953) described //. nodulisporus 

 with truly nodulose spores. Singer (1955) made this the type of the 

 genus Hygroaster. In H. schidzeri we agree that the 1 spore wall is 

 minutely punctate-warty or at times slightlv wrinkled-warty. In gen- 

 eral, the spores of Hygrophorus are seldom ornamented. One artifact 



