580 Long : Local Distribution and Occurrence of 



Most fungi, owing to their ephemeral nature, need an abundance 

 of water to make their food supply, quickly and sufficiently avail- 

 able ; therefore in localities visited by long-continued rains or having 

 an atmosphere laden with moisture, as well as in marshy districts 

 and dark damp forests where evaporation is retarded, fungi are found 

 in great quantities and of many species. On the contrary, when an 

 abundance of water is wanting we may expect to find only a limited 

 number of species. 



From the geological and climatic environments that exist, the 

 distribution and occurrence of fungi in this vicinity is found to be 

 limited by three very important factors : (i) The nature of the soil, 

 (2) The paucity of densely wooded areas, especially of large damp 

 forests, and (3) The climatic conditions. 



Discussing each of these factors more specifically, we find that 

 the soils in the vicinity of Austin, are formed mainly from limestone 

 detritus and with little vegetable debris in them. The innumerable 

 hillsides and slopes cause much of the surface soil, which contains 

 the vegetable matter, to be washed away, leaving a soil deficient 

 in humus and incapable of nourishing fungi. 



The habitat of the majority of our saprophytic fungi is in the 

 valleys and under the trees, especially under the cedars where the 

 debris of leaves, etc., cannot easily be washed away. In some locali- 

 ties clay, gravel or sandy soils are found but these are likewise defi- 

 cient in organic matter to such an extent that unless sheltered by 

 trees, very few species of fungi are found growing in them. As a 

 rule, then, the soil conditions of this vicinity are unfavorable to 

 fungal growths, except in old pastures where the % soil is rich from 

 the droppings of stock. Here we often find fungi in great quantities 

 as regards individuals but usually limited to a few species. 



The second condition, lack of deep, dense forests with their 

 ever-present humus in the debris at their roots, excludes a large 

 number of shade-loving species. Our trees, mainly oaks and 

 cedars, are not tall and compact, nor are they sufficiently massed 

 to form dark, damp places, consequently the quantity of humus 

 formed and retained in the soil beneath them is small and not suffi- 

 cient to encourage or promote the growth of fungi to any great 

 extent. 



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The third condition, that of climate, is the most potent factor 



