914 
Journal of Agricultural Research 
Vol. XXVIII, No. 9 
produced perithecia. In later experiments, perithecia have been found only in 
tubes or Petri dishes planted with Y 15 and Y 29 or with Y 15 and some other 
strain, but the yield has been smaller. 
PERITHECIA 
Macroscopically the perithecia are very similar to those of Gibberella saubi- 
netii. Possibly this explains the fact that they have not been reported on corn. 
Microscopically there is not the least difficulty in distinguishing the ascospores 
of the two. The straight, usually 1-septate ascospores of the moniliform fungus, 
so constricted normally at the septa as to give the spore a swollen appearance 
(PI. 2, C, D; fig. 5), contrast sharply with the curved, 3-septate ascospores of 
G. saubinetii , normally not constricted at the septa. 
Ten representative ascospores from each of the substrata noted in Table III 
were measured and the averages of these measurements are given in Table III. 
It will be noted, as previously mentioned, that most of the ascospores are 1- 
septate. 
Table III.— Average sizes of 1-, 2-, and 3-septate ascospores , respectively, from 
cultures in each of which both strain Y 15 and strain Y 29 had been planted , and 
percentages of the 1-, 2-, and 3-septate ascospores , respectively, from the different 
substrata 
Age of 
Substratum 
Average sizes and percentages of each group in the total number— 
culture 
1 -septate 
2 -septate 
3-septate 
Days 
61_ 
Oat agar... 
Per 
cent 
Microns 
4. 54 by 15.00 
4.82 by 15.83 
4.40 by 15.32 
4. 51 by 15. 55 
3.95 by 14.47 
Per 
cent 
Microns 
Per 
cent 
Microns 
4.62 by 17.32 
None seen. 
55.. 
Sterilized wheat head_ 
55__. 
Oat agar... 
4.43 by 16.04 
None seen. 
54_ 
Sterilized wheat head_ 
55... 
Potato-dextrose agar_ 
Sterilized wheat head_ 
52 
21 
4.08 by 14. 78 
4. 01 by 14.78 
4.38 by 17.40 
27 
4.31 by 15.36 
4.13 by 16.90 
4.32 by 17.40 
91_ __ 
86 
4. 35 by 15.86 
4.38 by 15.47 
9 
5 
75. 
Potato-dextrose agar_ 
_do.... 
69 
15 
16 
74_ .. 
61 
17 
22 
73.. 
_do.. 
97 
4.31 by 17. 78 
4.41 by 15.66 
3 
4.42 by 18.53 
4.37 by 16.93 
Average. _ __ 
4.16 by 15.65 
CONIDIAL CULTURES FROM ASCOSPORES 
Single germinating ascospores, sufficiently isolated in poured plates so that 
they could be removed singly, were transplanted to agar slants in test tubes. 
Such a germinating ascospore, photographed through the bottom of the Petri 
dish before transferring, is shown in Plate 2, A. This colony transferred, be¬ 
came Fusarium strain Ai. A similar colony is shown in Plate 2, B. Still another 
similar colony from a 1-septate ascospore was isolated in a similar way and 
became Fusarium strain A 2 . 
While these Fusarium strains agreed in general with strains Y 15 and Y 29, 
including the production of microspores in moniliform chains, they have not 
shown the tendency of Y 29 to produce sporodochia. In form the macroconidia 
of strains Ai and A 2 (fig. 6) are very similar to those of strains Y 15 and Y 29 
(fig. 2 to 4). Ten representative macroconidia from strains Ai and A 2 from each 
of the sources as noted in Table IV were measured and the averages are given. 
It will be noted that likewise in size the macroconidia of strains Ai and A 2 are 
very similar to those of strains Y15 and Y 29 but that the former tend to aver¬ 
age somewhat longer, except in the case of the 5-septate conidia of strain Y 29. 
