Fiisarinm in Tttber Rot and Wilt of Potato 
11 
The first inoculations were made in December 1914. The cut 
ends of 20 Early Ohio tubers were wetted with spore suspensions 
of F. trichothccioides and 5 tubers were kept as controls. Four 
inoculated and one control potato were kept in each compartment 
at a temperature of 25° C. in an almost saturated atmosphere. 
After 4 weeks all of the inoculated tubers were in advanced stages 
of rot. 
On January 31, 3 potatoes were inoculated according to the 
second method with F. oxyspontm, and 3 with F. trichothecioides, 
and kept at 20° C. until February 17. Two of the former set were 
slightly rotted and one totally, while the entire latter set was rotted 
severely. The controls showed no rot (fig. 1). 
On January 15 another series was started which was kept at a 
temperature ranging from 15-20° C. until February 15. Six sets 
of 3 tubers each were started and each set was kept in a separate 
sterile chamber, 2 tubers of each set being inoculated by smearing 
cut surfaces with agar grown inoculum. Sets I, II, and III were 
inoculated with F. oxysporiim, and sets IV, V, and VI with F. tri- 
chothccioides. In set I, one inoculated tuber was rotted, while the 
other and the control were sound ; in set II, one was deeply rotted 
and the others sound ; in set III, one was deeply rotted and the 
others sound ; in set lY , two were rotted and the control sound ; 
in set Y , two tubers were rotted slightly and the control sound ; and 
in set \l, two tubers were rotted and the control sound. 
F. oxysporum and F. trichothccioides were re-isolated from these 
rotted tubers by placing tissue cut from such tubers on plated glu- 
cose agar. Nothing other than the organism with which the tuber 
had been inoculated developed. Inoculum from these plates was 
used in infecting tubers again with the same results. 
Since these results were at variance with the statements of 
WoLLENWEBiiR the experiments were repeated with hundreds of 
tubers, and the results were verified. 
Discussion. — Tubers inoculated with F. oxysporum did not 
develop the ring discoloration that is considered characteristic of 
the activity of F. oxysporum, but a general rot of the whole tuber. 
Generally, however, this was not a dry rot, l^ut a rot that resembles 
more the soft rots of bacterial origin, although it is not accompanied 
