206 Investigations in Plant Pathology 



I was glad to see that you had had a chance to go to the western and 

 southern hnes of the field of your labor. As you justly remark, it pays 

 to study these diseases and all the conditions possible. I am overjoyed 

 at my opportunity to study my matter in Europe, and I feel that I will 

 lose nothing in the end even if it will cost me about a thousand dollars 

 besides losing several months salary. 



It gives one confidence in his opinion to know that he has seen and 

 studied his subject over as much or more of a field than have those who 

 have propounded their theories. I assure you this is a rich field for study 

 in our line. Everything in the Vegetable Kingdom is diseased here, and 

 many new forms of disease — so far as we are concerned. I have been 

 obliged to stay here much longer than I expected, but I have felt as you 

 wrote that I would regret it if I spared either time or money while here. 

 I have placed some material in alcohol for you from Syracuse and I believe 

 I have some dry material from one or two other points — I mean of the 

 peach aphis. I have some facts, material and photos, relative to peach 

 diseases here which will interest you, I am sure. No. " yellows " has 

 been seen thus far in any part of Europe. . . . Peach leaf -curl is very bad 

 in France but not so bad in Italy as Sicily. 



Tuberculosis of the olive has given me a study of deep interest as it is 

 one of the few diseases which has been proven as caused by bacteria. I 

 have collected a considerable amount of good material. Have formed the 

 friendship of Dr. Savastano vv^ho did the work on this disease at the 

 Zoological Laboratory at Naples where there is a bacteriological outfit. 

 Savastano is a fine fellow and is located at the Agricultural School at 

 Portici, where prof[essor] Comes is, and where Dr. Giglioli is Director. 



Pierce also used photography in aid of his studies in southern 

 France, Italy, and the eastern half of Sicily. Returning to America, 

 he immediately began to prepare his report on the California vine 

 disease,"^ and, since the olive industry was " becoming one of 

 importance on the Pacific coast," he prepared an article on " Tuber- 

 culosis of the Olive" which was published April 30, 1891 by the 

 Journal of Mycology.^- Bacteriological investigations of the Cali- 

 fornia vine disease *'^ — those performed by Pierce in California 

 and those done by Galloway at Washington— had yielded only 

 negative results; at least, thus far, no causal connection between 

 the isolated bacteria of the vine inner tissue and the disease had 

 been established beyond questioning. 



One night, while at Washington during the period Pierce 



" Bulletin No. 2, Division of Vegetable Pathology, U. S. Dep't of Agric, 

 Washington, Gov't Print. Otlice, 1892, entitled, The California vine disease. A 

 preliminary report of investigations. 



"■6 (4): 148-153. 



'* The California vine disease, preliminary report, 208. 



