Pomona College Journal of Economic Botany. 



327 



Unless otherwise stated the cultures were kept in a glass case in the interior 

 of the laboratory. The descriptions are given for reflected light and a 

 white ground. 



Nutrient agar (M4). The descriptions are given for plate cultures. 

 Carnation strains of Fusariuin grew vigorously, developing a light cottony 

 growth. A culture normally increased its diameter 10 mm. each 24 hours. 

 Growth was always accompanied by the development of color of varying 

 density. Strain (E) developed color more profusely than the other strains; 

 first a wine red color developed which appeared most intense in the two 

 concentric zones corresponding to the zones of greatest mycelium growth. 

 (Plate II. Figure 2 and Plate IV, e.) Older cultures developed a sulphur 

 yellow' color irregularly over the plate. Strain (R) developed the same 

 colors in a less degree, and strain (IV) sometimes produced the red or 

 pink tinges, but usually only a slight yellow coloration was observed. 

 (Plate III. Figures 1 and 2, and Plate IV, b.) 



The potato strains grew less rapidly; a culture increased its diameter 

 about 7 mm. per day. A slight yellowish color appeared about the twelfth 

 or fifteenth day. Strain (H) always formed a depressed growth and con- 

 centric and radial lines were often prominent. (Plate II, Figure 1.) Strain 

 (VII) always formed a cottony growth about 4 mm. high and sometimes 

 suflficiently uneven to give the effect of concentric rings. 



' Nutrient agar (M3). Growth of the various strains on this medium 

 closely reseinbled the growth on (M4), except in color which developed less 

 readily. 



Beet agar (M2). The descriptions are given for slant tube cultures. 

 The carnation strains closely resembled each other in growth ; each produced 

 a vigorous cottony mycelium, accompanied from the beginning by the devel- 

 opment of a wine red color, and in three to five days by the development 

 of a sulphur yellow color. Cultures thirty days old developed a copper 

 green amidst the yellow. A dense pellicle formed on the surface of the 

 slant. This was deep blood red below and shaded into lighter tints of 

 wine red above. The center of the culture was yellow and green, and the 

 aerial growth extending above the tip of the slant remained white. (Plate 

 IV. Figures a, d and e.) 



The potato strains differed in their growth. Strain (H) formed a 

 depressed growth, very pale salmon in color, except for a slight cottony 

 growth extending above the upper tip of the slant. (Plate IV. Figure f.) 

 Strain (VII) formed a cottony mycelium about 4 mm. high, slightly rose 

 pink, and a thin pdliclo shading from rose pink Ix'low to creamy yellow 

 above. 



Prune juice and bread (]\I5). The descriptions are given for flask 

 cultures! Carnation strains were very similar in growth, each producing 

 an even cottony mycelium about 10 mm. high and spreading over the surface 

 of the medium in ten or twelve days. Color developed about the tenth day. 



