276 THE PLANT WORLD 



turity. Some of the Tricholomas endure the rigors of early 

 frosts. Tn the spring, before the frost is out of the ground, 

 CoUybhi phitpliylla Fries, Pluteus cerv'uuts Schaeffer, and 

 Peziza occidentaJis Schweinitz make their appearance. Species 

 of Copriuiis were collected this year in the month of March. 



Moisture is an important factor in the life of fungi, but 

 many species exhibit considerable power of adjustment and 

 resist continued dry weather. At the same time, copious 

 rains do not always insure large crops of fungi. The rain- 

 fall for the months of May, June, and July, 1907, was about 

 the normal, yet fungi were extremely scarce in western Penn- 

 sylvania. The old haunts, where in former years it was an 

 easy matter to fill several collecting baskets on a trip, were 

 a barren region. It is not easy to assign a cause for this, 

 but the low temperature during that period may partially 

 explain the scarcity of early summer forms. 



It is an interesting fact that in the immediate vicinity 

 of Pittsburg very few of the common species of rusts 

 and smuts are found. After leaving the smoke covered hills 

 and valleys, and arriving in the regions beyond the smoke, 

 they become numerous. It would seem that the fumes from 

 the mills act as a fungicide. 



Fungal societies are not so stable and fixed as the so- 

 cieties of higher plants, and it hardly seems expedient at 

 present to attempt a classification on this basis; nevertheless 

 there are edaphic or local associations, which show as evi- 

 dent relations to the substratum as do the associations of 

 flowering plants. Near Kittanning, Pennsylvania, there is 

 a gently sloping hill cov^ered with various deciduous trees. 

 On this hill there appears each year an abundant crop of 

 Lactarii. Bushels of these might be gathered. At Ohiopyle, 

 Pennsylvania, around the Park Hotel, situated in an open 

 grove, Amanitas grow in profusion. Tn Allegheny cemetery, 

 Pittsburg, two years ago, a lawn containing several acres was 

 carefully manured in the spring. Tn the months of August 

 and September of the same year the whole lawn was literally 



