Placed on a Nation-widu Basis 183 



work \vc arc cn^aqcd in a collection of funL;i is absolutely necessary; 

 realizing this, we have spared no elTort to make the herbarium what it 

 should be. Three years a^o the number of specimens in the collection did 

 not exceed three thousand; now there are somelhint; over fourteen thousand 

 named, labeled, and mounted on seven thousand herbarium sheets. During 

 the year a lart;e number of economic funt;i have been collected, one assistant 

 spending a month in the field engaged in this work.*'' 



Pierce explained why lie sent materials to Washington: 



After a long series of observations, made on material from various 

 portions of the diseased district, which in no case failed to disclose the 

 diseased vines as swarming with these bodies in all portions where sap 

 had a ready flow, I believed it proper to undertake a series of experiments 

 to determine if these bodies, always present, bore any relation to the disease 

 as a whole. I had little doubt that they were microorganisms and gave to 

 the local spotting of the leaves their characteristically sharp outline. 

 Cultures from various parts of the vine were made in agar-agar and other 

 media. Three sorts of bacteria were found with enough constancy to 

 warrant further study, but I have not so far been able to determine whether 

 any of these are the cause of the disease. Healthy vines were procured, 

 set, and inoculated; but in due time I found both inoculated and control 

 plants showing signs of disease. Owing to our inability, thus demon- 

 strated, to make a fair test of the action of the germs in the infected district, 

 these and analogous experiments — such as grafting, the testing of hardy 

 stocks, etc. — have been inaugurated at Washington, outside infection being 

 carefully guarded against. ^^ 



Before Pierce concluded his first period of investigation in 

 California, he secured translations of foreign literature and studied 

 the similarity of other vine diseases: Mai nero, Folletage or 

 Apoplexie, and Oidhim especially. He soon established that 

 Phylloxera did not cause the disease he was studying. His study 

 of " every order of insect," several saprophytic and some parasitic 

 fungi, root fungi, termites, nematodes, and the many physical 

 factors investigated, were to be continued, including study of the 

 effect of long continued propagation of vines from cuttings. He 

 found "no good evidence that seedlings [would] exist longer 

 [against] this disease than vines long propagated from cuttings." 

 He appears to have early contemplated two possible solutions: 

 first, to import healthy cuttings from disease-free areas, and, 

 second, to attempt grafts of resistant grape species onto susceptible 

 varieties. On Muscat as well as Mission vines Bordeaux mixture, 



^° op. cit., 420-421. " Op. cit.. All. 



