360 Journal of Agricultural Research Voi. xix, No. s 



(c) Both Feronia limonia and Feroniella lucida of the subtribe Fero- 

 ninae have been successfully inoculated. While the spots are typical of 

 those described for the rutaceous group, they can develop in the absence 

 of wounds. 



{d) Of the plants tested in the subtribe Lavanginae, Hesperthusa 

 ci'enulata, while producing very non typical spots, is quite susceptible in 

 that infection can take place on the leaves and twigs. Triphasia trifolia 

 and Severinia buxifolia have remained immune. 



(e) All plants of the subtribe Citrinae which have been tested have 

 been infected. Citr apsis Schweinfurthii is weakly positive; Atalaniia 

 citrioides and A. ceylonica are easily infected; Eremocitrus glauca. Micro- 

 citrus australasica, M. australasica var. sanguinea, M. australis and M. 

 Garrowayi, plants native to Australia, are rather susceptible in that 

 leaves, twigs, thorns, and branches are attacked; all four species of kum- 

 quat have been successfully infected; Fortunella margarito., F. japonica, 

 and F. eras sif alia exhibited considerable resistance, while F. Hindsii is 

 very susceptible; and Poncirus trifoliata is extremely susceptible. 



(/) Although working under entirely different conditions and using 

 different methods of inoculating plants, Lee's results with the wild rela- 

 tives check with those obtained by the senior author in the greenhouse, 

 with one exception. 



ig) In the field, only the wild relatives which were most susceptible 

 under greenhouse conditions have been successfully inoculated. Of these 

 Poncirus trifoliata and Microcitrus australis have proved to be susceptible, 

 while M. australasica and Fortunella Hindsii are somewhat susceptible. 

 Hesperthusa crenulata reacts to caxiker in about the same degree in the 

 field as in the greenhouse. 



(h) So far as the menace of citrus-canker to the Citrus industry of the 

 United States is concerned, with the exception of Poncirus trifoliata, 

 none of the wild relatives, native or introduced, now growing in the 

 Citrus districts are susceptible enough to have any bearing on the eradi- 

 cation program. 



(3) Little or no change in the susceptibility or resistance to citrus- 

 canker has been noted among the Citrus fruits from that previously indi- 

 cated. All plants tested have been successfully inoculated. 



(a) The plants of the grapefruit and pummelo group are extremely 

 susceptible, with the exception of the Hirado Bun tan and Siamese pum- 

 melos. 



(6) Of the numbers tested belonging to Citrus hystrix, those with 

 rounded leaves are as susceptible as grapefruit. The plants with pointed 

 leaves are apparently more resistant. 



(c) All numbers of lemons tested, including the Ichang lemon, show 

 about equal susceptibility, which is slightly less than that for grapefruit. 



(d) As a whole, the plants of the sweet-orange group are slightly less 

 susceptible than the lemons. Citrus excelsa and the Natsu-mikan can 

 be classed with the sweet orange in susceptibility. ' 



