86 
in morphological characters, and was of little differential value. On 
either washed agar or plain agar there was excellent linear growth but 
poor color and little conidia-production. Bean agar gave too luxuriant 
vegetative growth. Brazil-nut agar was useful for the development 
of white mycelium for use in nutrition studies and for study of proteolytic 
action. The other agars used showed no special features of value. 
RICE AND SIMILAR SUBSTANCES AS MEDIA, WITH SPECIAL 
NOTE OF COLOR PHENOMENA 
Rice in test-tubes —Rice was prepared in the customary way, by placing 
it in test-tubes to.a depth of one centimeter, adding enough water to 
stand 1 cm. above it, and then autoclaving. This medium, so useful in 
the study of many fungi, notably of Fusarium, proved very interesting 
here. At the expiration of about two weeks from the time of inoculation— 
generally the most profitable time for first observation—three zones or 
regions could usually be recognized: (1) the region recently invaded by 
the fungus, which I designate as the recent region; (2) the region first 
invaded, which had assumed nearly its final appearance, and which I call 
the old region; and (3) the region midway between 1 and 2, which I shall 
call the median region. 
Each of these regions showed characters of its own. Within all of 
them, but particularly in the old and in the median regions, there were 
three points to observe: (a) the places where the rice grains came in contact 
with the glass, which places I call contact; (b) the spaces between rice grains, 
at first filled by water, which I call the interstices; and (c) the line between 
interstices and contacts, which I term the border. Usually the fungus 
grows down into the interstices, consumes their contents, and fills the 
remaining space more or less completely with mycelium. Penetration 
of the contacts is very slow and may not occur at all, therefore they are 
usually but slowly discolored by the passage of various chemicals into them. 
The border is the region of greatest development, and often presents a 
sharp, distinct line of pronounced character. It is the contrasts furnished 
by the contacts, interstices, and borders, often attended by the develop- 
ment of beautiful and vivid colors, that give to these cultures their strik- 
ing appearance. In addition to these characters the final appearance of the 
rice column should be noted. It is sometimes digested away in characteristic 
manner. The development or absence of sclerotia is also noteworthy. 
H. No. 1, in rice test-tubes, at two weeks, gave, in the recent region, 
salmon-colored interstices, contacts, and borders; in the median regions the 
