126 ''Sleepy Disease'' of the Tomato 



, Per cent, of 



microsclerotia 

 produced as esti- 

 mated in amount 

 Group Isolation of surface of 

 no. no. medium covered 



12 



39 

 43 



II 2 10 

 27 

 35 



III 4 30 

 40 

 47 



IV 1 50 

 22 

 45 



V 3 70 

 13 

 30 



VI 5 100 

 32 

 33 



In each case F. alho-atrum was isolated from the diseased plants. 

 Even after four months there was no sign of yellowing or wilting of the 

 inoculated elms, but they were shorter than the controls and F. alho- 

 atrum was isolated from the wood 2 inches above the inoculation point. 



6. Ecology. 

 Temperature. 



The temperature relations of numerous fungi in pure culture have 

 been studied in detail, but it is only within the last decade or so that the 

 temperature factor has been related to the process of infection. This is 

 largely the result of investigations carried out by the pathologists in the 

 Bureau of Plant Industry in the United States Department of Agriculture 

 and more particularly by Prof. L. R. Jones and his colleagues at the 

 University of Wisconsin (18, 13, 9, etc.). 



Such work is important especially in connection with the cultivation 

 of crops under glass, where it is a simple matter to regulate the tempera- 

 ture. Observations made during the present investigation indicated an 

 intimate relation between temperature conditions and inoculation results 

 and showed the necessity for further inquiry into this relationship. As 

 a series of glasshouses, where different temperatures could be maintained 



