GENERAL INFORMATION ii 



forms on wheat uredospores and teleutospores ; 

 while the same fungus when growing on the bar- 

 bery [Berderis vulgaris) produces aecidiospores and 

 picnospores. 



On making a study of saprophytic fungi, it is 

 found that the particular form of spore produced 

 depends upon the conditions of food, temperature, 

 air supply, moisture, etc. ; provided these remain 

 constant, so does the form of the spore ; but change 

 any or all of the factors, and a change in the spore 

 formation usually results. Moving the mycelium 

 of some fungi from a rich nutritive medium into a 

 poorer one, or into distilled water, will immediately 

 result in a chancre of fructification. In a similar 

 manner lack of water, or lack of food, will cause 

 change. It will be seen then that diversity in the 

 type of reproduction serves a most useful purpose 

 to the funo^us in case of emergfencies ; in that al- 

 though the conditions may be unfavourable to 

 growth, and the mycelium may die in consequence, 

 the spores remain to perpetuate the species, when 

 and if more favourable conditions are afforded. 

 In combating any disease this should be carefully 

 borne in mind. 



Just as gooseberry bushes may be increased in 

 number by putting detached portions under favour- 

 able conditions for growth, so also can small por- 

 tions of mycelium serve to increase the amount of 

 fungus growth. This method of increase, however. 



