60 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. ^ 



preceding year. These samples, like all others, were sucked from the 

 comb cells into sterilized pipettes and we had the judgment of Mr. 

 E. R. Root of Medina, Ohio, that the samples were largely fresh apple 

 blossom honey with only a little admixture of dandelion. They, 

 therefore, approximated as closely as honey samples could do, the 

 composition of apple blossom nectar in which the baciUi are known to 

 thrive. None of these samples yielded the blight bacillus. However, 

 we do not positively know that blight bacilli were present in the blos- 

 soms to which the bees from four of these hives had access; we do 

 definitely know that they were present in a large percentage of the 

 blossoms on which the bees from one of the hives pastured, but from 

 which we obtained no blight, though honey samples were taken from it 

 at intervals up till midsummer. 



To determine if it is possible for the organism to live in honey as it 

 does in nectar, and inferentially, that the bacilU can be scattered from 

 the hive, we inoculated with the blight organism samples of steri- 

 lized honey, of varying age, from the freshest nectar-like samples we 

 could obtain from the combs to samples taken in midsummer, and then 

 cultured from these samples at intervals for the purpose of determining 

 how long the bacilH would remain virile in this medium. Cultures 

 were made on agar and incubated in the laboratorj' and then parallel 

 or confirmatory series of inoculations were made into young apple 

 shoots. Both pure honey and 50 per cent honey, diluted with water so 

 as to more nearly approximate the composition of nectar, were used. 

 The number of cultures made was 176 and the number of inoculations 

 made closely approximated 600. Some 400 to 500 check twigs were 

 numbered and examined for comparison. After incubating in honey 

 from Sy2 minutes to several days, the organism was cultured by the 

 poured plate and streak methods on 3 per cent neutral nutrient 

 glucose agar. Growth of the organism was obtained from the 83/2- 

 minute incubation and also on intermediate incubations up to and 

 including 43 hours and 25 minutes. This isolated organism, when 

 inoculated into the growing tips of apple shoots, usually gave 100 per 

 cent of infection on trees where no infection occurred on check or 

 uninoculated shoots. The inoculated shoots were protected against 

 other means of infection by being enclosed in paraffined paper bags. 

 Some of the inoculations were made into the shoots of small potted 

 apple trees kept growing in the greenhouse and among which no blight 

 had ever existed. The results with these potted trees exactly agreed 

 with those obtained when working with orchard trees. 



A- fresh culture of B. amylovorus was inoculated into a tube of un- 

 sterilized honey and incubated there from 4 to 47 hours. At the end 

 of the 4th, the 28th, and the 47th hour, inoculations were made from 



