Jan. 14, 191S Cultures of Wood-Rotting Fungi on Artificial Media 37 



TEMPERATURE RECORDS 



During the entire time the cultures were under observation, two 

 thermographs were run continuously. One was placed on the shelf 

 with the fungi exposed to sunlight. A soil thermograph was used to 

 record the temperature of the tubes kept in the dark. 



DEFINITION OF TERMS USED 



It was foimd early in the study of the cultural characters of the fungi 

 under consideration that a set of descriptive terms especially adapted 

 to the cultures of fungi grown under the conditions here described would 

 have to be used. The terms employed in the tables in this paper and 

 in the body of the text are those usually found in ordinary botanical litera- 

 ture, but they have been modified somewhat to fit the conditions ob- 

 taining for fungus growth. The fungus growth on artificial media is 

 divided by the writers into two general classes, aerial and submerged. 

 The aerial mycelium consists of that which is on or above the surface of 

 the agar; the submerged mycelium includes all that is beneath the surface 

 of the agar. 



Great difficulty was found in obtaining appropriate terms which 

 would express the character of growth of the aerial mycelium. In de- 

 scribing this aerial growth terms which are usually used in describing 

 the pubescence of leaf surfaces have been employed. In other words, 

 the surface of the agar is considered as the surface of a leaf and the 

 character of the mycelium growing on this surface is discussed in terms 

 of leaf pubescence with some minor modifications made necessary by 

 the character of the organism under discussion. The following terms as 

 used by the writers require special definition, since they depart in some 

 instances from the usually accepted definitions of these terms: 



Appressed: Mycelium which is prostrate on ttie surface of the agar. This with 

 •many fungi is the first stage in the aerial growth of the mycelium. Later this appressed 

 mycelium may give place to other forms. 



Cobwebby: Long, weak, intertangled hairs which are not thick enough to be either 

 woolly or felty and are not short enough to be considered as downy. 



Cottony: Erect, rather long (3 to 5 mm.) mycelium spreading in all directions. 



Downy: Short, fine hairs, loosely scattered over the surface of the mycelium, giving 

 it a downy appearance. 



Felty: Matted with intertwined hairs, resembling felt. 



Floccose : Scattered patches of short mycelium. 



Plumose: Tufts of mycelium with a central axis from which short hyphae radiate. 



Silky: Long parallel threads of mycelium, more or less prostrate, like combed silk. 



Sodden: Mycelium having a water-soaked appearance; usually such myceliiun is 

 appressed. 



Subfelty: A thin layer of mycelium consisting of short intertwined hairs. 



Velvety: Layer of mycelium with distinct, dense, straight, short hairs like pile of 

 velvet. 



Woolly: A dense mass of mycelium consisting of long, tortuous, matted hairs. 

 Cottony and woolly may both later become felty by the long hairs becoming matted 

 and prostrate. 



