NISHIMURA: A CARRIER OF THE MOSAIC DISEASE 229 
9. Inoculation of the apple of Sodom with juice of infected tobacco 
plants 
Before making the above experiments with the alkeKengi I 
had already satisfied myself as to the relation of the mosaic of 
tobacco to that of the apple of Sodom. 
Forty young healthy plants of apple of Sodom (4-6 inches 
high) were used in each of the two series. The first series was 
inoculated on March 27 with juice from diseased apple of Sodom. 
The second series was inoculated on March 25 with juice from 
diseased tobacco. These inoculations were made by method 
No. 5. In the first series thirty-three plants showed mosaic. 
The incubation period was from eight to ten days. In the second 
series thirty-six plants showed mosaic. The. incubation period 
was from seven to twelve days. In every case the mosaic symp- 
toms appeared on the first or second new leaves that were formed 
after inoculation. The incubation period was much the same in 
all these experiments. Twenty-five controls were kept and after 
thirty days they were found to be in healthy condition. 
The appearance of the mosaic leaves of apple of Sodom, pro- 
duced by infection from the carrier, P. Alkekengi (which had been 
inoculated from apple of Sodom or from tobacco) is the same as in 
the case of direct infection from tobacco or apple of Sodom in the 
distribution of the dark green with relation to the veins, in the 
blistering, etc. There can be no question that the virus induces 
the same symptoms after passing through the apparently immune 
plant to another as when transferred directly from one susceptible 
to the disease. 
10. Reinoculation of tobacco plants 
The N. Tabacum plants inoculated in experiments 2, 3, and 4, 
which did not take the disease, were later used for further inocu- 
lations with virus from the diseased tobacco which had been 
inoculated from P. Alkekengi. September 10 the fourteen plants 
of N. Tabacum were inoculated by method No. 1. September 18, 
plants 3 and 5 showed the mosaic on the first new leaves. Sep- 
tember 19, plants 7 and 11 also showed the mosaic on the first new 
leaves. September 20, plants 8, 10 and 12 showed the mosaic. 
September 21, plants 2, 6 and 9 showed the mosaic. September 
