204 MAIXE AGRICULTURAL EXPERIMENT STATION. I913. 



mine whether the fungus which is being studied has been 

 described. In some cases, an investigator after making an 

 extended study of a species of this genus has described it as 

 new because of the impossibility of placing it among those 

 already described and at the same time has pointed out the pos- 

 sibility that it may have been incompletely described under 

 another name. These new species however in which the descrip- 

 tions take into consideration the characters of the fungus under 

 different conditions of growth make it possible to determine 

 with a considerable degree of certainty whether a fungus which 

 is being studied agrees with the description or not. In some 

 cases the account of the study of a species may become so 

 extended as to make it difficult for the reader to pick out the 

 most important points. It would be very desirable if each per- 

 son who works with a species of Fusarium would either keep 

 the fungus in culture or would send a culture to a laboratory 

 which would keep it growing so that others who desire to do 

 so may obtain it for comparison. In the study of this genus, 

 the comparison of species grown side by side under the same 

 conditions is very desirable. 



Interest in the genus has increased with the knowledge that a 

 number of very important plant diseases are caused by species 

 of Fusarium. There can be little question that with further 

 study it will 'be found that some of them which have been 

 regarded as saprophytes are parasites which cause a considerable 

 amount of damage to living plants. Owing to the difffculty in 

 determining the species and the amount of cross inoculation 

 work which should be done in order to determine the extent of 

 the parasitism of each, a large amourt of study is necessary in 

 order to come to definite knowledge in regard to the character- 

 istics of each and its importance as a cause of disease. 



On account of the lack of knowledge of the diseases caused 

 by species of Fusarium in Maine, although such fungi were 

 frequently encountered in the examination of diseased plant 

 tissues, it has seemed desirable to make some study of the forms 

 isolated from dift'erent hosts and to test their pathogenicity by 

 means of inoculation experiments. 



In the study of the fungi responsible for the decay of Maine 

 apples, two species of Fusarium Avere isolated from decaying 

 fruit in 1908. These fungi were grown in pure culture and 



