34 



rather more representative of the country as a whole geographically 

 than the strains in the larger of Peltier's experiments, though less 

 representative as to host sources. The number is too small to justify 

 conclusions as to the proportion of Corticium vagum strains which 

 can be expected to prove strongly virulent on pine. The data are 

 offered merely as a beginning, to which it is hoped experimenters 

 with other strains of C. vagum will make additions. 



In addition to the strains used in these two experiments, several 

 others which had been lost or for other reasons could not be included 

 in both the final experiments had been previously tested on pines in 

 earlier experiments. Of these, 6 strains, 1 each from alfalfa, sugar 

 beet, Pseudotsuga taxifolia, Pinus banksiana, P. resinosa^ and P. 

 strobus, gave indications of low virulence on the pines; 3 strains, 1 

 each from sugar beet, Pinus sylvestris, and P. ponderosa, gave indi- 

 cations of rather high virulence ; while another strain from P. potide- 

 Tosa indicated an intermediate ability to attack pine. Combining 

 these strains with those represented in figure 13, there are data on 27 

 original strains, of which 8 are roughly classed as strongly virulent 

 on pine seedlings, 14 as weak, and 5 as intermediate. 



Edson and Shapovalov (40) have conducted inoculation experi- 

 ments on potato stems with 6 of the Corticium strains which had 

 been used on pine, including the 5 strains mentioned by them on page 

 218 and their strains R. XV (the writer's strain 192 of fig. 2) on page 

 215. Strains 147 and 724, which had proved the most destructive 

 in the inoculations on pine, appeared also rather strongly virulent on 

 potato. Strain No. 186, originally from potato, which had given no 

 definite evidence of parasitism on pine, also prpved unable to cause 

 lesions on the potato stems. The remaining 3 strains, all of inter- 

 mediate virulence on pine, gave results on potato which were less in- 

 dicative of agreement with the order of virulence on pine. The data 

 suggest that strains strongly parasitic on potato are likely to be 

 strongly parasitic on pine, and vice versa, but the agreement between 

 their results and the writer's is not sufficiently complete to establish 

 the point. 



FUSARIUM SPP. 



Fusarium is often found on or in damped-oif seedlings (24, 46, 60, 

 94, 120, 137, 141, 142). The early inoculation experiments, conducted 

 in the main with strains not sufficiently described to allow their iden- 

 tification, have been recently summarized (68, p. 537), together with 

 descriptions of inoculation experiments on pine seedlings with four 

 commonly recognized species of Fusarium. These, though not fol- 

 lowed by reisolation, gave rather definite evidence that Fusarium 

 moniliforme Sheldon was decidedly parasitic and F. solani less 

 strongly so. Fusarium, ventricosum Appel and Wollenw. was indi- 



